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package Torello.HTML.Tools.Images;

import Torello.HTML.*;
import Torello.Java.*;

import Torello.HTML.NodeSearch.TagNodeFind;
import Torello.Java.Additional.Ret2;
import Torello.Java.Additional.Counter;
import Torello.Java.Shell.C;

import java.net.*;
import java.io.*;
import java.util.*;
import java.util.regex.*;
import java.util.function.*;
import javax.imageio.*;
import java.util.concurrent.*;
import java.util.concurrent.locks.*;

import java.awt.image.BufferedImage;

/**
 * A more advanced class for both downloading and saving a list of images, using URL's.
 * 
 * <BR /><BR /><EMBED CLASS="external-html" DATA-FILE-ID="ISR">
 */
public class ImageScraper
{
    /**
     * This is the default maximum wait time for an image to download ({@value}).  This value may
     * be reset or modified by instantiating a {@code ImageScraper.AdditionalParameters} class, and
     * passing the desired values to the constructor.  This value is measured in units of
     * {@code public static final java.util.concurrent.TimeUnit MAX_WAIT_TIME_UNIT}
     *
     * @see #MAX_WAIT_TIME_UNIT
     */
    public static final long        MAX_WAIT_TIME       = 10;

    /**
     * This is the default measuring unit for the {@code static final long MAX_WAIT_TIME} member.
     * This value may be reset or modified by instantiating a 
     * {@code ImageScraper.AdditionalParameters} class, and passing the desired values to the
     * constructor.
     *
     * @see #MAX_WAIT_TIME
     */
    public static final TimeUnit MAX_WAIT_TIME_UNIT  = TimeUnit.SECONDS;

    /** <EMBED CLASS="external-html" DATA-FILE-ID="ISUA"> */
    public static String USER_AGENT = "Chrome/61.0.3163.100";

    private final   Iterable<String>            source;
    private final   URL                         originalPageURL;

    private final   String                      targetDirectory;
    private final   TargetDirectoryRetriever    targetDirectoryRetriever;
    private final   ImageReceiver               imageReceiver;

    /**
     * A functional-interface that allows a user to specify where to save an image-file that
     * provides a list of details about the image before it is actually written to disk.
     * 
     * <BR /><BR /><EMBED CLASS="external-html" DATA-FILE-ID="TDR">
     */
    @FunctionalInterface
    public static interface TargetDirectoryRetriever extends java.io.Serializable
    {
        /** <EMBED CLASS="external-html" DATA-FILE-ID="SVUIDFI">  */
        public static final long serialVersionUID = 1;

        /**
         * The {@code dir(...)} method within this interface will be called each time that an image
         * successfully downloads from the internet.  It's purpose is to allow the programmer to
         * supply a target directory for where to store this downloaded image.  Implement the
         * lone-method from this interface, and images will be saved to individual save-directories
         * on an image-by-image basis.  If a {@code interface TargetDirectorieRetriever} is not
         * provided, then all images will be saved to a single target-directory (or the
         * {@code interface 'ImageReceiver"} must be implemented).
         *
         * @param url This is the {@code URL} that was used to connect to the internet, and
         * download the image in question.
         *
         * @param fileName This parameter will receive the computed filename of the image.
         *
         * @param imageFormat This identifies whether the image-in-question is a {@code GIF, JPG, 
         * PNG} etc...  Remember the image might not be saved by the same name which was used in 
         * the HTML on the website from which this was downloaded.
         *
         * @param iteratorCount <EMBED CLASS="external-html" DATA-FILE-ID="ISIC">
         *
         * @param successCount <EMBED CLASS="external-html" DATA-FILE-ID="ISSC">
         *
         * @return It is up to the user implement this method such that it returns a {@code String}
         * that identifies an appropriate directory in the local filesystem where the image may be
         * saved.
         */
        public String dir
            (URL url, String fileName, IF imageFormat, int iteratorCount, int successCount);
    }

    /**
     * A functional-interface that allows a user to save an image-file to a location of his
     * or her choosing.
     * 
     * <BR /><BR /><EMBED CLASS="external-html" DATA-FILE-ID="IMGR">
     */
    @FunctionalInterface
    public static interface ImageReceiver extends java.io.Serializable
    {
        /** <EMBED CLASS="external-html" DATA-FILE-ID="SVUIDFI">  */
        public static final long serialVersionUID = 1;

        /**
         * Implement this class if saving image files to a target-directory on the file-system is
         * not acceptable, and the programmer wishes to do something else with the downloaded
         * images.  The lone-method in this interface (the "save" method) will be invoked each
         * time and image is downloaded.
         *
         * @param url This is the {@code URL} that was used to connect to the internet, and
         * download the image in question.
         *
         * @param fileName This parameter will receive the computed filename of the image.
         *
         * @param imageFormat This identifies whether the image-in-question is a {@code GIF, JPG,
         * PNG, etc...}  Remember the image might not be saved by the same name which was used in
         * the HTML on the website from which this was downloaded.
         *
         * @param iteratorCount <EMBED CLASS="external-html" DATA-FILE-ID="ISIC">
         *
         * @param successCount <EMBED CLASS="external-html" DATA-FILE-ID="ISSC">
         *
         * @param image This is the newly downloaded image.
         */
        public void save(
            URL url, String fileName, IF imageFormat, int iteratorCount,
            int successCount, BufferedImage image
        );
    }

    /**
     * A functional-interface allowing a user to specify a file-name for an image, which provides
     * some details about the image before it is saved to disk.
     * 
     * <BR /><BR /><EMBED CLASS="external-html" DATA-FILE-ID="FNR">
     */
    @FunctionalInterface
    public static interface FileNameRetriever extends java.io.Serializable
    {
        /** <EMBED CLASS="external-html" DATA-FILE-ID="SVUIDFI">  */
        public static final long serialVersionUID = 1;

        /**
         * The intention of implementing this method is to provide the code with an 'adjusted'
         * file name for saving images downloaded from the internet.
         *
         * @param url This is the {@code URL} that was used to connect to the internet, and
         * download the image in question.
         *
         * @param imageFormat This identifies whether the image-in-question is a {@code GIF, JPG, 
         * PNG,} etc...  Remember the image might not be saved by the same name which was used in
         * the HTML on the website from which this was downloaded.
         *
         * @param iteratorCount <EMBED CLASS="external-html" DATA-FILE-ID="ISIC">
         * @param successCount <EMBED CLASS="external-html" DATA-FILE-ID="ISSC">
         *
         * @return utilizing the information provided in the method-signature, the programmer is
         * expected to provide a file-name for saving the image that was provided.
         */
        public String fileName(URL url, IF imageFormat, int iteratorCount, int successCount);
    }

    // *************************************************************************************
    // source is Iterable<URL>
    // *************************************************************************************

    private static final Iterable<String> URLVecToStringVec(Iterable<URL> source)
    {
        Vector<String> ret = new Vector<>();
        source.forEach((URL url) -> ret.add(url.toString()));
        return ret;
    }

    /**
     * Convenience Constructor.
     * <BR />Invokes: {@link #ImageScraper(URL, Iterable, String)}
     * <BR />Converts: {@code Iterable<URL>} to {@code Iterable<String>}
     */
    public ImageScraper(Iterable<URL> source, String targetDirectory)
    { this(null, URLVecToStringVec(source), targetDirectory); }

    /**
     * Convenience Constructor.
     * <BR />Invokes: {@link #ImageScraper(URL, Iterable, TargetDirectoryRetriever)}
     * <BR />Converts: {@code Iterable<URL>} to {@code Iterable<String>}
     */
    public ImageScraper(Iterable<URL> source, TargetDirectoryRetriever targetDirectoryRetriever)
    { this(null, URLVecToStringVec(source), targetDirectoryRetriever); }

    /**
     * Convenience Constructor.
     * <BR />Invokes: {@link #ImageScraper(URL, Iterable, ImageReceiver)}
     * <BR />Converts: {@code Iterable<URL>} to {@code Iterable<String>}
     */
    public ImageScraper(Iterable<URL> source, ImageReceiver imageReceiver)
    { this(null, URLVecToStringVec(source), imageReceiver); }

    // *************************************************************************************
    // source is Iterable<TagNode>, URL
    // *************************************************************************************

    private static final Iterable<String> TagNodeVecToStringVec(Iterable<TagNode> source)
    {
        Vector<String> ret = new Vector<>();
        source.forEach((TagNode tn) -> ret.add(tn.AV("src")));
        return ret;
    }

    /**
     * Convenience Constructor.
     * <BR />Invokes: {@link #ImageScraper(URL, Iterable, String)}
     * <BR />Converts: {@code Iterable<TagNode>} to {@code String[]} using
     * {@link TagNode#AV(String)}
     * 
     * @param source This may be any java {@code Iterable<TagNode>}.  The {@code TagNode's} are
     * expected to contain HTML {@code <IMG SRC="...">} tags.
     */
    public ImageScraper(Iterable<TagNode> source, URL originalPageURL, String targetDirectory)
    { this(originalPageURL, TagNodeVecToStringVec(source), targetDirectory); }

    /**
     * Convenience Constructor.
     * <BR />Invokes: {@link #ImageScraper(URL, Iterable, TargetDirectoryRetriever)}
     * <BR />Converts: {@code Iterable<TagNode>} to {@code @String[]} using
     * {@link TagNode#AV(String)}
     * 
     * @param source This may be any java {@code Iterable<TagNode>}.  The {@code TagNode's} are
     * expected to contain HTML {@code <IMG SRC="...">} tags.
     */
    public ImageScraper(
            Iterable<TagNode> source, URL originalPageURL,
            TargetDirectoryRetriever targetDirectoryRetriever
        )
    { this(originalPageURL, TagNodeVecToStringVec(source), targetDirectoryRetriever); }

    /**
     * Convenience Constructor.
     * <BR />Invokes: {@link #ImageScraper(URL, Iterable, ImageReceiver)}
     * <BR />Converts: {@code Iterable<TagNode>} to {code @String[]} using
     * {@link TagNode#AV(String)}
     * 
     * @param source This may be any java {@code Iterable<TagNode>}.  The {@code TagNode's} are
     * expected to contain HTML {@code <IMG SRC="...">} tags.
     */
    public ImageScraper(Iterable<TagNode> source, URL originalPageURL, ImageReceiver imageReceiver)
    { this(originalPageURL, TagNodeVecToStringVec(source), imageReceiver); }

    // *************************************************************************************
    // source is Iterable<String>, URL
    // *************************************************************************************

    /**
     * Constructor that allows a user to provide a set of {@code URL's} as {@code String's} to the
     * download mechanism.
     *
     * @param source This is a {@code Vector<String>} of Image {@code URL's} saved as a
     * {@code String}.
     *
     * @param originalPageURL <EMBED CLASS="external-html" DATA-FILE-ID="ISOPURL">
     *
     * @param targetDirectory When this constructor is used, this {@code String} parameter
     * identifies the directory to where files must be saved.
     *
     * @throws NullPointerException If any of the elements of the input {@code Iterable<String>}
     * are null elements, then this Exception shall be thrown.
     *
     * @throws WritableDirectoryException This constructor shall check that parameter
     * {@code 'targetDirectory'} exists on the file-system, and is writable.  A small, temporary,
     * file shall be written to check this.
     */
    public ImageScraper(URL originalPageURL, Iterable<String> source, String targetDirectory)
    {
        this.source                     = source;
        this.originalPageURL            = originalPageURL;

        // Ensures that the target directory exists, and is writable
        WritableDirectoryException.check(targetDirectory);

        // Makes sure that the directory ends with a slash / file-separator.
        if (! targetDirectory.endsWith(File.separator)) if (targetDirectory.length() > 0)
            targetDirectory = targetDirectory + File.separator;

        this.targetDirectory            = targetDirectory;
        this.targetDirectoryRetriever   = null;
        this.imageReceiver              = null;

        if (source == null)
            throw new NullPointerException("parameter source is null");

        if (targetDirectory == null)
            throw new NullPointerException("parameter targetDirectory is null");
    }

    /**
     * Constructor that allows a user to provide a set of {@code URL's} as {@code String's} to
     * the download mechanism.
     *
     * @param source This is a {@code Vector<String>} of Image {@code URL's} saved as a
     * {@code String}.
     *
     * @param originalPageURL <EMBED CLASS="external-html" DATA-FILE-ID="ISOPURL">
     *
     * @param targetDirectoryRetriever This parameter must implement the static-inner
     * {@code class TargetDirectoryRetriever}.  This parameter allows the programmer to make a 
     * decision where image-files are stored after they are downloaded one a file-by-file basis.
     *
     * @throws NullPointerException If any of the elements of the input {@code Iterable<String>}
     * are null elements, then this Exception shall be thrown.
     */
    public ImageScraper(
        URL originalPageURL, Iterable<String> source,
        TargetDirectoryRetriever targetDirectoryRetriever
    )
    {
        this.source                     = source;
        this.originalPageURL            = originalPageURL;
        this.targetDirectory            = null;
        this.targetDirectoryRetriever   = targetDirectoryRetriever;
        this.imageReceiver              = null;

        if (source == null)
            throw new NullPointerException("parameter source is null");

        if (targetDirectoryRetriever == null)
            throw new NullPointerException("targetDirectoryRetriever is null");
    }

    /**
     * Constructor that allows a user to provide a set of {@code URL's} as {@code String's} to the
     * download mechanism.
     *
     * @param source This is a {@code Vector<String>} of Image {@code URL's} saved as a
     * {@code String}.
     *
     * @param originalPageURL <EMBED CLASS="external-html" DATA-FILE-ID="ISOPURL">
     *
     * @param imageReceiver This parameter allows the programmer to circumvent the "save-to-file"
     * portion of the code, and instead send the downloaded image to this interface.
     *
     * @throws NullPointerException If any of the elements of the input {@code Iterable<String>} 
     * are null elements, then this exception shall be thrown.
     */
    public ImageScraper(URL originalPageURL, Iterable<String> source, ImageReceiver imageReceiver)
    {
        this.source                     = source;
        this.originalPageURL            = originalPageURL;

        this.targetDirectory            = null;
        this.targetDirectoryRetriever   = null;
        this.imageReceiver              = imageReceiver;

        if (source == null)
            throw new NullPointerException("parameter source is null");

        if (imageReceiver == null)
            throw new NullPointerException("imageReceiver is null");
    }

    // *************************************************************************************
    // *************************************************************************************
    // More available download configuration parameters
    // *************************************************************************************
    // *************************************************************************************

    /**
     * A class that allows a user to further configure how images are downloaded.
     * 
     * <BR /><BR /><EMBED CLASS="external-html" DATA-FILE-ID="ADPA">
     */
    public static class AdditionalParameters
    {
        /** <EMBED CLASS="external-html" DATA-FILE-ID="SVUID"> */
        public static final long serialVersionUID = 1;
    
        /**
         * When this field is <B>TRUE</B>, if an attempt to download an image generates an
         * exception, the exception-throw <I>will not halt the download</I>, but rather the image
         * will be skipped, and download attempt will be performed on the next image in the list.
         * The exception will be stored in the {@code 'Results'} return object.
         */
        public final boolean skipOnIOException;

        /**
         * When this field is null, it is ignored; but if this field is not null, then before any
         * {@code URL} is connected for download, the downloaded mechanism will ask this
         * {@code URL-Predicate} for permission first.  If this {@code Predicate} returns
         * <B>FALSE</B> for a particular <B>URL,</B> that image will not be downloaded, and
         * instead, skipped.
         */
        public final Predicate<URL> skipURL;

        /**
         * When this field is null, it is ignored; but if not null, this {@code String} will be
         * <I>prepended</I> to each file-name that is saved or stored to the file-system.
         */
        public final String fileNamePrefix;

        /**
         * When true, images will be saved according to a counter; when this is <B>FALSE</B>, the
         * software will attempt to save these images using their original filenames - picked from
         * the <B>URL</B>.  Saving using a counter is the default behaviour for this class.
         */
        public final boolean useDefaultCounterForImageFileNames;

        /**
         * When this field is null, it is ignored; but if not null, each time an image is written
         * to the file-system, this <CODE>java&#46;util&#46;function&#46;Function&lt;URL,
         * String&gt;</CODE> will be queried for a file-name before writing the the image-file to
         * the file-system.  If this field is non-null, but images are being sent to
         * {@code Consumer<BufferedImage, IF> downloadedImageAltTarget}, rather than being saved
         * to the file-system, then this field is <I>also ignored</I>.
         */
        public final FileNameRetriever getImageFileSaveName;

        /**
         * This scraper has the ability to decode and save {@code Base-64} Images, and they may be
         * downloaded or skipped - <I>based on this {@code boolean}</I>.  If an
         * {@code Iterable<TagNode>} is passed to the constructor, and one of those
         * {@code TagNode's} contain an Image Element
         * ({@code <IMG SRC="data:image/jpeg;base64,...data">}) this class has the ability to
         * interpret and save the image to a regular image file.  By default, {@code Base-64}
         * images are skipped, but they can also be downloaded as well.
         */
        public final boolean skipBase64EncodedImages;

        /**
         * If you do not want the downloader to hang on an image, which is sometimes an issue
         * depending upon the site from which you are making a request, set this parameter, and the
         * downloader will not wait past that amount of time to download an image.  The default
         * value for this parameter is {@code 10 seconds}.  If you do not wish to set the
         * max-wait-time "the download time-out" counter, then leave the parameter
         * {@code "waitTimeUnits"} set to {@code null}, and this parameter will be ignored.
         */
        public final long maxDownloadWaitTime;

        /**
         * This is the "unit of measurement" for the field {@code long maxDownloadWaitTime}.
         * <BR /><BR /><B>NOTE:</B> <I>This parameter may be {@code null}, and if it is
         * <SPAN STYLE="color: red;"> both <B>this</B> parameter and the parameter <B>{@code long
         * maxDownloadWaitTime}</B> will be ignored</SPAN></I>, and the default maximum-wait-time
         * (download time-out settings) will be used instead.
         *
         * <BR /><BR /><B>READ:</B> java.util.concurrent.*; package, and about the {@code class
         * java.util.concurrent.TimeUnit} for more information.
         */
        public final TimeUnit waitTimeUnits;

        /**
         * Use this constructor to instantiate this class.  Read what each of these parameters
         * means to the downloader, by reading the comment information for each of these fields
         * in this class (above).
         *
         * @param skipOnIOException This will "skip" an image, and prevent the downloading process from
         * halting if an image fails to download
         *
         * @param skipURL A java {@code Predicate} for deciding which images should be skipped.
         * This parameter may be 'null.'  If it is, it will be ignored, and the downloader will
         * attempt to download all images.
         *
         * @param fileNamePrefix A standard Java-{@code String} may be inserted before the
         * file-name of each image downloaded, as a 'file-name prefix'.  This parameter may be
         * null, and if it is file-name prefixes will not be used.
         *
         * @param useDefaultCounterForImageFileNames It is usually a good idea to replace the
         * file-name for an image retrieved from a web-site with a simple, three-digit,
         * counter-name.  Image file names on a web-site can often be long {@code PKID Strings}
         * obtained from {@code SQL} database queries. To use a standard "counter" set this
         * parameter to <B>TRUE</B>.
         *
         * @param getImageFileSaveName This parameter may be used to convert image file-names used
         * on a web-page to user-generated image-file-names.  This parameter may be null, and if it
         * is - it will be ignored.  If this parameter is non-null, it takes precedence over the
         * {@code boolean} passed to parameter {@code 'useDefaultCounterForImageFileNames'}
         *
         * @param skipBase64EncodedImages This will order the downloader to convert and save HTML
         * Image Elements whose image-data was encoded into HTML Element, itself, using
         * {@code Base-64} Image-Encoding.  Thumbnails and other small images are sometimes stored
         * on web-pages using such encoding.
         *
         * @param maxDownloadWaitTime This parameter will be ignored unless a non-null value has
         * been passed to parameter {@code 'waitTimeUnits'}.  This may be used to prevent the
         * downloader from hanging when collecting images for a web-page.
         *
         * @param waitTimeUnits This is java {@code class TimeUnit} parameter for describing what
         * units are being used for the previous parameter, {@code 'maxDownloadWaitTime'}.
         */
        public AdditionalParameters(
            boolean                 skipOnIOException,
            Predicate<URL>          skipURL,
            String                  fileNamePrefix,
            boolean                 useDefaultCounterForImageFileNames,
            FileNameRetriever       getImageFileSaveName,
            boolean                 skipBase64EncodedImages,
            long                    maxDownloadWaitTime,
            TimeUnit                waitTimeUnits
        )
        {
            this.skipOnIOException                      = skipOnIOException;
            this.skipURL                                = skipURL;
            this.fileNamePrefix                         = fileNamePrefix;
            this.useDefaultCounterForImageFileNames     = useDefaultCounterForImageFileNames;
            this.getImageFileSaveName                   = getImageFileSaveName;
            this.skipBase64EncodedImages                = skipBase64EncodedImages;
            this.maxDownloadWaitTime                    = maxDownloadWaitTime;
            this.waitTimeUnits                          = waitTimeUnits;

            if (maxDownloadWaitTime < 0) throw new IllegalArgumentException(
                "You have passed a negative number for parameter maxDownloadWaitTime, and this is " +
                "not allowed here."
            );
        }

        /**
         * This constructor will return an instance of {@code AdditionalParameters} whose values
         * provide the following <B>MOST COMMON</B> behaviour choices:
         *
         * <BR /><TABLE CLASS="BRIEFTABLE">
         * <TR><TH>Parameter</TH><TH>Value</TH></TR>
         * <TR><TD>{@code skipOnIOException}</TD><TD>{@code TRUE}</TD></TR>
         * <TR><TD>{@code useDefaultCounterForImageFileNames}</TD><TD>{@code TRUE}</TD></TR>
         * <TR><TD>{@code skipBase64EncodedImages}</TD><TD>{@code FALSE}</TD></TR>
         * <TR><TD COLSPAN="2"><I>All other parameters set to 'null', and will be ignored.</I>
         * </TD></TR>
         * </TABLE>
         */
        public AdditionalParameters()
        { this(true, null, null, true, null, false, 0, null); }
    }

    // *************************************************************************************
    // *************************************************************************************
    // Results inner class
    // *************************************************************************************
    // *************************************************************************************

    /**
     * After downloading, class <CODE>ImageScraper</CODE> returns an instance of this class.
     * 
     * <BR /><BR /><EMBED CLASS="external-html" DATA-FILE-ID="ISRES">
     */
    public static class Results
    {
        /**
         * The java serializable tools can be very beneficial for saving the state of a program you
         * are testing.  Though it is unlikely a programmer would want to transmit this
         * 'results-report' class around (or at least I cannot think of much use), saving the state
         * of web-page scrape and all the testing routines that have been used is something that
         * can be really helpful.  <I><SPAN STYLE="color: red;">This is why most of the classes
         * that can be created / instantiated - a.k.a. non-static classes - implement the
         * Serializable interface</SPAN></I>.  It's a great debugging tool.
         */
        public static final long serialVersionUID = 1;

        /**
         * This will contain a complete list of the {@code URL's} that were retrieved (or generated-
         * <I>if partially-resolved 'relative' {@code URL's} occurred</I>).  Every image downloaded
         * (or attempted for download) will have its {@code URL} saved here.
         *
         * <BR /><BR />The index of this array will be parallel to the input-source {@code URL}
         * retrieval order.
         */
        public final URL[] urls;

        /**
         * If the "skip" {@code Predicate} declares that a particular image-download should not be
         * attempted, <I>FALSE</I> will be stored in this array.
         *
         * <BR /><BR />The index of this array will be parallel to the input-source {@code URL}
         * retrieval order.
         */
        public final boolean[] skipped;

        /**
         * The names of the files that were retrieved and/or stored will be in this array.
         * If this image were skipped or an exception occurred, the array position for that
         * {@code URL} would contain 'null'.
         *
         * <BR /><BR />The index of this array will be parallel to the input-source {@code URL}
         * retrieval order.
         */
        public final String[] fileNames;

        /**
         * The location of the file-name saved directory, if an image did not successfully save to
         * the file system, or if an {@code ImageReceiver} were used, then the array-location would
         * contain {@code 'null'}.
         *
         * <BR /><BR />The index of this array will be parallel to the input-source {@code URL}
         * retrieval order.
         */
        public final String[] saveDirectories;

        /**
         * The image type of the files that were retrieved will be stored in this array.
         *
         * <BR /><BR />The index of this array will be parallel to the input-source {@code URL}
         * retrieval order.
         */
        public final IF[] imageFormats;

        /**
         * If an image download fails, this will contain a record of the exception.
         *
         * <BR /><BR />The index of this array will be parallel to the input-source {@code URL}
         * retrieval order.
         *
         * <BR /><BR />If the download succeeded, then the associated array location would contain
         * 'null.'
         */
        public final Exception[] exceptions;

        /**
         * This will contain a list of long-integers, each of which will have the file-size of the
         * downloaded image.  If the programmer has elected for the {@code 'ImageReceiver'} option
         * - <I>rather than direct download of the images to the underlying file-system</I> (save to
         * lambda, instead of save-as-file) - then the "fileSize" will be a calculated file-size,
         * and not reflect the actual size of any file on the file-system.  Obviously, this is
         * because no file was created!
         *
         * <BR /><BR />The index of this array will be parallel to the input-source {@code URL}
         * retrieval order.
         */
        public final long[] sizes;

        /**
         * This will contain a list of integers, each of which shall have the image-widths of the 
         * downloaded images.
         *
         * <BR /><BR />The index of this array will be parallel to the input-source {@code URL}
         * retrieval order.
         */
        public final int[] widths;

        /**
         * This shall contain a list of integers, each of which shall have the image-heights of 
         * the downloaded images.
         *
         * <BR /><BR />The index of this array will be parallel to the input-source {@code URL}
         * retrieval order.
         */
        public final int[] heights;

        /** next result received array position. */
        int pos = 0;

        /** number of successfully saved images. */
        int successCounter = 0;

        /** When images are downloaded, log information may be sent here */
        Appendable log = null;

        Results(int size, Appendable log)
        {
            this.log = log;

            urls                = new URL[size];
            skipped             = new boolean[size];
            fileNames           = new String[size];
            saveDirectories     = new String[size];
            imageFormats        = new IF[size];
            exceptions          = new Exception[size];
            sizes               = new long[size];
            widths              = new int[size];
            heights             = new int[size];

            for (int i=0; i < size; i++)
            {
                urls[i]             = null;
                skipped[i]          = false;
                fileNames[i]        = null;
                saveDirectories[i]  = null;
                imageFormats[i]     = null;
                exceptions[i]       = null;
                sizes[i]            = -1;
                widths[i]           = -1;
                heights[i]          = -1;
            }
        }

        void nullURL() throws IOException // The Appendable throws this
        {
            if (log != null) log.append
                ("\t\t" + C.RED + "No URL was passed, or URL not found." + C.RESET + '\n');

            skipped[pos]            = true;
            pos++;
        }

        void urlException(String src, Exception e) throws IOException // The Appendable throws this
        {
            if (log != null) log.append(
                "\t\t" + C.RED + "Failed Instantiate URL, src = " + src + ", " +
                e.getClass().getName() + ": " + e.getMessage() + C.RESET + '\n'
            );

            skipped[pos]            = true;
            exceptions[pos]         = e;
            pos++;
        }
    
        void skippedURL(URL url) throws IOException // The Appendable throws this
        {
            if (log != null) log.append("\t\t" + C.YELLOW + "*** SKIPPING" + C.RESET + '\n');

            urls[pos]               = url;
            skipped[pos]            = true;
            pos++;
        }

        void downloadException(URL url, Exception e) throws IOException // The Appendable throws this
        {
            String msg = (e.getMessage() != null) 
                ? e.getMessage()
                : "no exception-message provided, [e.getMessage()==null]";

            if (log != null) log.append(
                "\t\t" + C.RED + "DOWNLOAD-EXCEPTION:\t" + e.getClass().getName() + ": " + msg + C.RESET + '\n' +
                "\t\t" + "While Downloading URL:\t" + url.toString() + '\n'
            );

            urls[pos]               = url;
            skipped[pos]            = true;
            exceptions[pos]         = e;
            pos++;
        }

        void imageReceiverSuccess
            (URL url, String fileName, IF ext, long size, int width, int height)
            throws IOException // The Appendable throws this
        {
            if (log != null) log.append(
                "\t\t" + C.YELLOW + "Successfully sent [" + fileName + '.' + ext.extension + "] to class ImageReceiver" + C.RESET + '\n'
            );

            urls[pos]               = url;
            fileNames[pos]          = fileName + '.' + ext.extension;
            imageFormats[pos]       = ext;
            sizes[pos]              = size;
            widths[pos]             = width;
            heights[pos]            = height;
            pos++;
            successCounter++;
        }

        void saveSuccess(
                URL url, String targetDirectory, String fileName, IF ext, long size,
                int width, int height
            )
            throws IOException // The Appendable throws this
        {
            if (log != null) log.append(
                "\t\t" + C.YELLOW + "File Saved:\t" + targetDirectory + fileName + "." +
                ext.extension + C.RESET + '\n'
            );

            urls[pos]               = url;
            saveDirectories[pos]    = targetDirectory;
            fileNames[pos]          = fileName + '.' + ext.extension;
            imageFormats[pos]       = ext;
            sizes[pos]              = size;
            widths[pos]             = width;
            heights[pos]            = height;
            pos++;
            successCounter++;
        }

        void saveFail(URL url, String targetDirectory, String fileName, IF ext, Exception e)
             throws IOException // The Appendable throws this
        {
            if (log != null) log.append(
                "\t\t" + C.RED + "***FILE-SAVE-EXCEPTION:\t" + targetDirectory + fileName + "." +
                ext.extension +
                "\t\t" + e.getClass().getName() + ": " + e.getMessage() + C.RESET + '\n'
            );

            urls[pos]               = url;
            skipped[pos]            = true;
            saveDirectories[pos]    = targetDirectory;
            fileNames[pos]          = fileName + '.' + ext.extension;
            imageFormats[pos]       = ext;
            exceptions[pos]         = e;
            pos++;
        }

        void skipB64(String imgFormatStr, String encodedPartialStr)
            throws IOException // The Appendable throws this
        {
            if (log != null) log.append(
                "\t\t" + C.YELLOW + "Skipping B64 Encoded String: " + imgFormatStr + ", " + encodedPartialStr + C.RESET + '\n'
            );

            skipped[pos]            = true;
            pos++;
        }

        void b64ConvertException(Exception e)
            throws IOException // The Appendable throws this
        {
            if (log != null) log.append
                ("\t\t" + C.RED + "Error Converting and Decoding Base-64 Image" + C.RESET + '\n');

            skipped[pos]            = true;
            exceptions[pos]         = e;
            pos++;
        }
    }

    /**
        ******************************************************
        class ImageScraper
        ******************************************************
        Iterable<String>                    source;
        URL                                 originalPageURL;

        String                              targetDirectory;
        TargetDirectoryRetriever            targetDirectoryRetriever;
        ImageReceiver                       imageReceiver;

        ******************************************************
        class ImageScraper.AdditionalParameters
        ******************************************************
        boolean                             skipOnIOException;
        Predicate<URL>                      skipURL;
        String                              fileNamePrefix;
        boolean                             useDefaultCounterForImageFileNames;
        FileNameRetriever                   getImageFileSaveName;
        long                                maxDownloadWaitTime
        TimeUnit                            waitTimeUnits
    */

    // *************************************************************************************
    // *************************************************************************************
    // download methods
    // *************************************************************************************
    // *************************************************************************************

    /**
     * Convenience Method.
     * <BR />Invokes: {@link #download(AdditionalParameters, Appendable)}
     * <!-- NOTE: JavaDoc Upgrader REMOVES EXCEPTION THROWS... DO NOT MOVE THIS METHOD -->
     */
    public Results download()
        throws IOException, MalformedURLException, URISyntaxException
    { return download(null, null); }

    /**
     * This will iterate through the {@code URL's} and download them.  Note: Both the
     * {@code AdditionalParameters} and {@code 'log'} parameters may be null, and if they are, they
     * will be ignored.
     *
     * @param a This parameter takes customization requests for batch image downloads.  This 
     * parameter can be passed 'null' and when it is, customizations shall be ignored.
     * 
     * <BR /><BR /><B>SKIP ON EXCEPTION:</B> The most useful feature of the {@code class 
     * AdditionalParameters} is to facilitate a download where invalid or out-dated {@code URL's}
     * do not cause the download mechanism to break - which normally would require running an
     * image-download from the beginning.  There is a simple {@code AdditionalParameters}
     * constructor that quickly builds an instance of that class to have {@code boolean
     * skipOnIOException} initialized to <B>TRUE</B>.
     * 
     * @param log This shall receive text / log information.  If this parameter receives 'null',
     * it will be ignored.
     *
     * <EMBED CLASS="external-html" DATA-FILE-ID="APPENDABLE">
     *
     * @return an instance of {@code class Results} for the download.  The {@code class
     * ImageScraper.Results} contains several parallel arrays with information about images that
     * have downloaded.  If an image-download happens to fail due to an improperly formed {@code
     * URL} (or an 'incorrect' {@code URL}), then the information in the {@code Results} arrays 
     * will contain a 'null' value for the index at those array-positions corresponding to the
     * failed image.
     *
     * @throws IOException This might throw if there is an {@code IOException} when downloading an
     * image, or attempting to save an image to the file-system.  If the
     * {@code AdditionalParameters 'a'} parameter is set to suppress-exceptions (and continue to the
     * next Image {@code URL}, via the {@code boolean skipIOExceptions}), then this exception will
     * never throw.
     *
     * @throws MalformedURLException This will throw if there are problems de-referencing the
     * {@code URL's}.  If the {@code AdditionalParameters 'a'} parameter is set to 
     * suppress-exceptions (and continue to the next Image {@code URL}, via the {@code boolean
     * skipIOExceptions}), then this exception will never throw.
     *
     * @throws URISyntaxException Same as {@code MalformedURLException.}  Will not throw if 
     * exceptions are ignored.
     */
    public Results download(AdditionalParameters a, Appendable log)
        throws IOException, MalformedURLException, URISyntaxException
    {
        // Compute the size of the input, will make array-building much faster
        Counter counter = new Counter();
        source.forEach(url -> counter.addOne());

        Results     results = new Results(counter.size(), log);
 
        for (String src : source) 
            if (src == null)
            {
                results.nullURL();
                if ((a != null) && a.skipOnIOException) continue;
                else throw new NullPointerException("One of the SRC URL's was null.");
            }
            else
            {
                Matcher m = IF.B64_INIT_STRING.matcher(src);
                if (m.find())   CONVERT_B64(m.group(1), m.group(2), results, a);
                else            DOWNLOAD(COMPUTE_URL(src, results, a), results, a);
            }

        return results;
    }

    // *************************************************************************************
    // *************************************************************************************
    // Internal COMPUTE-URL / FILENAME Methods
    // *************************************************************************************
    // *************************************************************************************

    private void CONVERT_B64(
            String imageFormatStr, String b64EncodedImage, Results results,
            AdditionalParameters a
        )
        throws IIOException, IOException
    {
        if (results.log != null) 
            results.log.append(
                "\tBASE-64 IMAGE:\t" + imageFormatStr + ',' + b64EncodedImage.substring(0, 40) + '\n'
            );

        if ((a == null) || ((a != null) && a.skipBase64EncodedImages))
        {
            results.skipB64(imageFormatStr, b64EncodedImage.substring(0, 15));
            return;
        }

        IF              ext;
        BufferedImage   image;
        try {
            ext     = IF.get(imageFormatStr);
            image   = IF.decodeBase64ToImage(b64EncodedImage, ext);
            //image   = IF.decodeBase64ToImage_V2(b64EncodedImage, ext);
        } catch (Exception e)
        {
            results.b64ConvertException(e);
            if ((a != null) && a.skipOnIOException) return;
            throw e;
        }
        String fileName = FILENAME(null, ext, results, a);
        HANDLE_DOWNLOADED_IMAGE(null, fileName, ext, results, a, image);
    }

    private URL COMPUTE_URL(String src, Results results, AdditionalParameters a)
        throws IOException, URISyntaxException
    {
        if (results.log != null)
            results.log.append("\tChecking / Converting SRC-URL string:\t" + src + '\n');

        if (StrCmpr.startsWithXOR_CI(src.trim(), "http://", "https://"))

            try
                { return new URL(URLs.toProperURLV7(src)); }

            catch(MalformedURLException e)
            {
                results.urlException(src, e);
                if ((a != null) && a.skipOnIOException) return null;
                else throw e;
            }
            catch(URISyntaxException e)
            {
                results.urlException(src, e);
                if ((a != null) && a.skipOnIOException) return null;
                else throw e;
            }

        else if (originalPageURL == null)
        {
            MalformedURLException ex = new MalformedURLException(
                "You have passed a null 'originalPageURL' parameter, but at least one of the URL's " +
                "you have passed for downloading is either a partial URL, or else an invalid URL: " +
                "[" + src + "]"
            );

            results.urlException(src, ex);

            if ((a != null) && a.skipOnIOException) return null;
            else                                    throw ex;
        }

        Ret2<URL, MalformedURLException> ret = Links.resolve_KE(src, originalPageURL);

        if (ret == null) // I do not think this case is possible.  I'll leave it here anyway.
        {
            results.nullURL();
            return null;
        }
        if (ret.b != null)
        {
            results.urlException(src, ret.b);
            if ((a != null) && a.skipOnIOException) return null;
            else throw ret.b;
        }

        // ADDED in NOVEMBER, 2019
        // This micro-detail is the case where the "Resolved URL" also has ASCII-Escape characters
        // that need to be escaped.  This is rare, but it needs to be heeded.  If there are
        // ASCII-Escape character (which must be escaped).   Then "toProperURLV8" will handle that
        // well enough.
        //
        // CONSIDER IT: Post-Processing of the "Resolve URLs" class

        try
            { return new URL(URLs.toProperURLV8(ret.a)); }

        catch(MalformedURLException e)
        {
            results.urlException(src, e);
            if ((a != null) && a.skipOnIOException) return null;
            else throw e;
        }
        catch(URISyntaxException e)
        {
            results.urlException(src, e);
            if ((a != null) && a.skipOnIOException) return null;
            else throw e;
        }
    }

    private String FILENAME(URL url, IF ext, Results results, AdditionalParameters a)
    {
        String fileName = ((a != null) && (a.fileNamePrefix != null)) ? a.fileNamePrefix : "";

        if ((a != null) && (a.getImageFileSaveName != null))
            fileName = fileName + a.getImageFileSaveName.fileName
                (url, ext, results.pos, results.successCounter);

        else if ((a == null) || ((a != null) && a.useDefaultCounterForImageFileNames))
            fileName = fileName + StringParse.zeroPad(results.successCounter);

        else
        {
            fileName = url.getFile().substring(1);
            if (fileName.toLowerCase().endsWith('.' + ext.extension))
                fileName = fileName.substring(0, fileName.length() - 1 - ext.extension.length());
        }
        return fileName;
    }

    // *************************************************************************************
    // *************************************************************************************
    // Internal Download Methods
    // *************************************************************************************
    // *************************************************************************************

    /**
     * If this class has been used to make "multi-threaded" calls that use a Time-Out wait-period,
     * you might see your Java-Program hang for a few seconds when you would expect it to exit back
     * to your O.S. normally.
     *
     * <BR /><BR /><B><SPAN STYLE="color: red;">NOTE:</B></SPAN>
     * {@code AdditionalParameters.maxDownloadWaitTime, AdditionalParameters.waitTimeUnits} operate
     * by building a "Timeout &amp; Monitor" thread.  Thusly, when a program you have written
     * yourself reaches the end of its code, <I><B>if you have performed any time-dependent
     * Image-Downloads using {@code class ImageScraper}</B></I>, then your program <I>might not
     * exit immediately,</I> but rather sit at the command-prompt for anywhere between 10 and 30
     * seconds before this Timeout-Thread  dies.
     *
     * <BR /><BR /><B><SPAN STYLE="color: red">MULTI-THREADED:</B></SPAN> You may immediately
     * terminate any additional threads that were started using this method.
     */
    public static void shutdownTOThreads() { executor.shutdownNow(); }

    // ******************************
    private static final    ExecutorService executor    = Executors.newCachedThreadPool();
    private static final    Lock            lock        = new ReentrantLock();
    // ******************************

    private void DOWNLOAD(URL url, Results results, AdditionalParameters a) throws IOException
    {
        BufferedImage	image;
        if (url == null) return;

        Appendable log = results.log;
        if (log != null) log.append("\tIMAGE-URL:\t\t" + url.toString() + '\n');

        if ((a != null) && (a.skipURL != null) && (a.skipURL.test(url) == true))
        { results.skippedURL(url); return; }

        // ******************************
        // *** ADDED on May 1st, 2019 ***
        // ******************************
        Callable<BufferedImage> threadDownloader = new Callable<BufferedImage>()
        {
            public BufferedImage call() throws Exception
            {
                try { return ImageIO.read(url); }
                catch (IIOException e)
                {   
                    // This will **sometimes** help when connecting to a URL "expects" this "User-Agent"
                    // This won't *always* work - or will it?  It is a very large-internet, with many MANY types of web-servers.
                    // THIS IS SORT-OF "ATTEMPT TO DOWNLOAD #2"
                    // try {
                    if (log != null) log.append("\tUSING USER-AGENT:\t" + url.toString() + '\n');
                    HttpURLConnection con = (HttpURLConnection) url.openConnection();
                    con.setRequestMethod("GET");
                    con.setRequestProperty("User-Agent", "Chrome/61.0.3163.100");
                    InputStream is = con.getInputStream();
                    return ImageIO.read(is);
                }
            }
        };

        lock.lock();
        Future<BufferedImage> future = executor.submit(threadDownloader);
        lock.unlock();

        long wt = ((a != null) && (a.waitTimeUnits != null)) 
            ? a.maxDownloadWaitTime 
            : MAX_WAIT_TIME;

        TimeUnit tu = ((a != null) && (a.waitTimeUnits != null)) 
            ? a.waitTimeUnits
            : MAX_WAIT_TIME_UNIT;

        try
            { image = future.get(wt, tu); }

        catch (TimeoutException e)
        {
            if (e.getMessage() == null) e = new TimeoutException
                ("Waited: " + wt + " " + tu.toString());

            results.downloadException(url, e);

            if ((a != null) && a.skipOnIOException) return;

            throw new IOException
                ("The download timed-out, see getCause() for more information.", e);
        }

        catch (ExecutionException e)
        {
            Exception cause = ((e.getCause() != null) && (e.getCause() instanceof Exception)) 
                ? (Exception) e.getCause() 
                : e;

            results.downloadException(url, cause);

            if ((a != null) && a.skipOnIOException) return;

            throw new IOException
                ("The download had an exception, see getCause() for more information.", cause);
        }

        catch (InterruptedException e)
        {
            results.downloadException(url, e);

            if ((a != null) && a.skipOnIOException) return;

            throw new IOException(
                "The download was interrupted by another thread, see this Throwable.getCause() " +
                "for more information.", e
            );
        }

        IF      ext         = IF.getGuess(url.toString());
        String  fileName    = FILENAME(url, ext, results, a);

        HANDLE_DOWNLOADED_IMAGE(url, fileName, ext, results, a, image);
    }

    private void HANDLE_DOWNLOADED_IMAGE(
            URL url, String fileName, IF ext, Results results,
            AdditionalParameters a, BufferedImage image
        )
        throws IIOException, IOException
    {
        Appendable log = results.log;

        String dirName = null;

        if (targetDirectory != null)
            dirName = targetDirectory;

        else if (targetDirectoryRetriever != null)
            dirName = targetDirectoryRetriever.dir
                (url, fileName, ext, results.pos, results.successCounter);

        else if (imageReceiver != null)
        {
            imageReceiver.save(url, fileName + '.' + ext.extension, ext, results.pos, results.successCounter, image);
            
            long l;
            {   // CODE COPIED FROM STACK-OVERFLOW.  This should probably become a separate-method. 
                //  I am not 100% it works yet.  (The "Green Check Mark" was not checked on this answer!)
                ByteArrayOutputStream tmp = new ByteArrayOutputStream();
                ImageIO.write(image, ext.extension, tmp);
                tmp.close();
                l = tmp.size();
            }
            results.imageReceiverSuccess(url, fileName, ext, l, image.getWidth(), image.getHeight());
            return;
        }

        else throw new IllegalStateException
            ("Not image-target specified.  Illegal State - is a constructor overloaded?");

        if (! dirName.endsWith(File.separator)) dirName += File.separator;

        File f = null;
        if (ext != null)
            try {
                String fName = dirName + fileName + '.' + ext.extension;
                if (log != null) log.append("\tAttempting to save file: " + fName + '\n');

                f = new File(fName);
                ImageIO.write(image, ext.extension, f);
                results.saveSuccess(
                    url, dirName, fileName, ext, f.length(),
                    image.getWidth(), image.getHeight()
                );
                return;
            } catch (Exception e)
            {
                results.saveFail(url, dirName, fileName, ext, e);
                if ((a != null) && a.skipOnIOException) return;
                throw e;
            }
        else
        {
            String fName = dirName + fileName + '.';
            for (IF imageFormat : IF.values())
                try {
                    f = new File(fName + imageFormat.extension);
                    ImageIO.write(image, imageFormat.extension, f);
                    results.saveSuccess(
                        url, dirName, fileName, imageFormat, f.length(),
                        image.getWidth(), image.getHeight()
                    );
                    return;
                }
                catch (javax.imageio.IIOException e)	{ f.delete(); 	continue; }
                catch (Exception e)
                {
                    e.printStackTrace();
                    results.saveFail(url, dirName, fileName, imageFormat, e);
                    if ((a != null) && a.skipOnIOException) return;
                    throw e;
                }
        }
    }

    // *************************************************************************************
    // *************************************************************************************
    // Localize Images methods
    // *************************************************************************************
    // *************************************************************************************

    /** 
      * Convenience Method.
      * <BR />Invokes: {@link #localizeImages(Vector, URL, Appendable, AdditionalParameters, String)}
      * <BR />Passes: null to {@link AdditionalParameters} and to root-{@code URL}
      * <BR /><B>WARNING:</B> Presumes there are no partial-{@code URL's}
      */
    public static Ret2<int[], ImageScraper.Results> localizeImages
        (Vector<HTMLNode> page, Appendable log, String downloadDirectory)
        throws IOException
    { return localizeImages(page, null, log, null, downloadDirectory); }

    /** 
      * Convenience Method.
      * <BR />Invokes: {@link #localizeImages(Vector, URL, Appendable, AdditionalParameters, String)}.
      * <BR />Passes: null to {@link AdditionalParameters}.
      */
    public static Ret2<int[], ImageScraper.Results> localizeImages
        (Vector<HTMLNode> page, URL pageURL, Appendable log, String downloadDirectory)
        throws IOException
    { return localizeImages(page, pageURL, log, null, downloadDirectory); }

    /**
     * Downloads images located inside an HTML Page and updates the {@code SRC=...} {@code URL's}
     * so that the links point to a <I>local copy</I> of <I>local images</I>.
     *
     * <BR /><BR />After completion of this method, an HTML page which contained any HTML image
     * elements will have had those images downloaded to the local file-system, and also have had 
     * the HTML attribute {@code 'src=...'} changed to reflect the local image name instead of the
     * Internet URL name.
     *
     * @param page Any vectorized-html page or subpage.  This page should have HTML {@code <IMG ...>}
     * elements in it, or else this method will exit without doing anything.
     *
     * @param pageURL If any of the HTML image elements have {@code src='...'} attributes that are
     * partially resolved or <I>relative {@code URL's}</I> then this can be passed to the
     * {@code ImageScraper} constructors in order to convert partial or relative {@code URL's}
     * into complete {@code URL's.}  The Image Downloader simply cannot work with partially
     * resolved {@code URL's}, and will skip them if they are partially resolved.  This parameter
     * may be null, but if it is and there are incomplete-{@code URL's} those images will
     * simply not be downloaded.
     *
     * @param log This is the 'logger' for this method.  It may be null, and if it is - no output
     * will be sent to the terminal.
     *
     * <EMBED CLASS="external-html" DATA-FILE-ID="APPENDABLE">
     *
     * @param ap This is the {@link AdditionalParameters} parameter that allows to further
     * specify the request to the Image Downloader.  See the documentation for this class for more
     * information.  This parameter may be null, and if it is, it will be ignored and default
     * behavior will occur.
     * 
     * <BR /><BR /><B>SKIP ON EXCEPTION:</B> The most useful feature of the {@code class
     * AdditionalParameters} is to facilitate a download where invalid or out-dated {@code URL's}
     * do not cause the download mechanism to break - which normally would require running an
     * image-download from the beginning.  There is a simple {@code AdditionalParameters} 
     * constructor that quickly builds an instance of that class to have
     * {@code boolean skipOnIOException} initialized to <B>TRUE</B>.
     *
     * @param downloadDirectory This File-System directory where these files shall be stored.
     *
     * @return An instance of {@code Ret2<int[], ImageScraper.Results>}.  The two returned elements
     * of this class include:
     *
     * <BR /><BR /><UL CLASS="JDUL">
     * <LI> {@code Ret2.a (int[])}
     *      <BR /><BR />This shall contain an index-array for the indices of each HTML
     *      {@code '<IMG SRC=...>'} element found on the page.  It is not guaranteed that each of
     *      images will have been resolved or downloaded successfully, but rather just that an HTML
     *      {@code 'IMG'} element that had a {@code 'SRC'} attribute.  The second element of this
     *      return-type will contain information regarding which images downloaded successfully.
     *      <BR /><BR />
     * </LI>
     * <LI> {@code Ret2.b (ImageScraper.Results)}
     *      <BR /><BR />The second element of the return-type shall be the instance of
     *      {@link ImageScraper.Results} returned from the invocation of
     *      {@code ImageScraper.download(...)}.  This method will provide details about each of the
     *      images that were downloaded; or, if the download failed, the reasons for the failure.
     *      <I>This return element shall be null if no images were found on the page.</I>
     *      <BR />
     * </LI>
     * </UL>
     * 
     * <BR />These return {@code Object} references are not necessarily important - <I>and they
     * may be discarded if needed.</I>  They are provided as a matter of utility if further
     * verification or research into successful downloads is needed.
     *
     * @see AdditionalParameters
     */
    public static Ret2<int[], ImageScraper.Results> localizeImages(
        Vector<HTMLNode> page, URL pageURL, Appendable log, AdditionalParameters ap,
        String downloadDirectory
    )
        throws IOException
    {
        int[]               imgPosArr   = TagNodeFind.all(page, TC.Both, "img");
        Vector<TagNode>     vec         = new Vector<>();

        // No Images Found.
        if (imgPosArr.length == 0) return new Ret2<int[], Results>(imgPosArr, null);

        for (int pos : imgPosArr) vec.addElement((TagNode) page.elementAt(pos));

        ImageScraper is = new ImageScraper(vec, pageURL, downloadDirectory);
        ImageScraper.Results r;

        try
            { r = is.download(ap, log); }
        catch (URISyntaxException e)
        {
            throw new IOException(
                "There was a problem de-referencing one of the partial-URL's from the page URL.  " +
                "See this methods's Throwable.getCause() for details.",
                e
            ); 
        }

        // ImageScraper.shutdownTOThreads(); 
        // NOTE-TO-READER: Need to call this method, or function will not shutdown.
        // NOTE: Commented out for now.

        ReplaceNodes.r(page, imgPosArr, (HTMLNode n, int arrPos, int count) ->
        {
            if (    (r.fileNames[count] != null)
                &&  ((r.exceptions[count] == null)
                &&  (r.skipped[count] == false)))

                return ((TagNode) page.elementAt(arrPos))
                        .setAV("src", r.fileNames[count], SD.SingleQuotes);

            else
                return (TagNode) n;
        });

        return new Ret2<int[], Results>(imgPosArr, r);
    }
}