* </p>
 * @author shinsuke
 * @param <E> the type of elements maintained by this set
 */
public class LruHashSet<E> extends AbstractSet<E> implements Set<E>, java.io.Serializable {
    private static final long serialVersionUID = 1L;

    /**
     * The internal LRU hash map used to store elements.
     */
    private final LruHashMap<E, Object> map;

    // Dummy value to associate with an Object in the backing Map

 * This exception indicates that an external command or process execution encountered an error.
 */
public class CommandExecutionException extends FessSystemException {

    private static final long serialVersionUID = 1L;

    /**
     * Constructor with error message.
     * @param message The error message describing the command execution failure.
     */
    public CommandExecutionException(final String message) {

 * that don't declare ServletException in their throws clause.
 */
public class ServletRuntimeException extends RuntimeException {

    /** Serial version UID for serialization compatibility. */
    private static final long serialVersionUID = 1L;

    /**
     * Constructs a new ServletRuntimeException wrapping the given ServletException.
     *
     * @param e The ServletException to wrap
     */

 * This exception is used for errors during theme installation, uninstallation, or configuration.
 */
public class ThemeException extends FessSystemException {

    private static final long serialVersionUID = 1L;

    /**
     * Constructs a new ThemeException with the specified message and cause.
     *
     * @param message the exception message
     * @param cause the underlying cause of this exception

 * This exception is used for errors during thumbnail creation and processing.
 */
public class ThumbnailGenerationException extends FessSystemException {

    private static final long serialVersionUID = 1L;

    /**
     * Constructs a new ThumbnailGenerationException with the specified message and cause.
     *
     * @param message the exception message

 */
@Deprecated
public class ConflictResolverNotFoundException extends Exception {
    // constants --------------------------------------------------------------

    /** The serial version ID. */
    private static final long serialVersionUID = 3372412184339653914L;

    // constructors -----------------------------------------------------------

    /**
     * Creates a new <code>ConflictResolverNotFoundException</code> with the specified message.

/**
 * @since 4.0.0
 */
@Experimental
public class ArtifactInstallerException extends MavenException {

    /**
     *
     */
    @Serial
    private static final long serialVersionUID = 3652561971360586373L;

    /**
     * @param message the message of the error
     * @param e {@link Exception}
     */
    public ArtifactInstallerException(String message, Exception e) {

/**
 * The Exception class throw by the {@link ProjectBuilder} service.
 *
 * @since 4.0.0
 */
@Experimental
public class ProjectBuilderException extends MavenException {

    @Serial
    private static final long serialVersionUID = -7629871850875943799L;

    /**
     * @param message the message to give
     * @param e the {@link Exception}
     */
    public ProjectBuilderException(String message, Exception e) {

/**
 * Exceptions thrown by the {@link SuperPomProvider} service.
 *
 * @since 4.0.0
 */
public class SuperPomProviderException extends MavenException {

    @Serial
    private static final long serialVersionUID = -8659892034004509331L;

    public SuperPomProviderException() {
        super();
    }

    public SuperPomProviderException(String message) {
        super(message);
    }

/**
 * The Exception class throw by the {@link ToolchainManager}.
 *
 * @since 4.0.0
 */
@Experimental
public class ToolchainManagerException extends MavenException {

    @Serial
    private static final long serialVersionUID = -9465854226608498L;

    /**
     * @param message the message to give
     * @param e the {@link Exception}
     */
    public ToolchainManagerException(String message, Exception e) {