private final Artifact artifact;

    VersionsMetadata(Artifact artifact, Date timestamp) {
        super(createRepositoryMetadata(artifact), (Path) null, timestamp);
        this.artifact = artifact;
    }

    VersionsMetadata(Artifact artifact, Path path, Date timestamp) {
        super(createRepositoryMetadata(artifact), path, timestamp);
        this.artifact = artifact;
    }

    private final PluginInfo pluginInfo;

    PluginsMetadata(PluginInfo pluginInfo, Date timestamp) {
        super(createRepositoryMetadata(pluginInfo), (Path) null, timestamp);
        this.pluginInfo = pluginInfo;
    }

    PluginsMetadata(PluginInfo pluginInfo, Path path, Date timestamp) {
        super(createRepositoryMetadata(pluginInfo), path, timestamp);
        this.pluginInfo = pluginInfo;
    }

    private final Collection<Artifact> artifacts = new ArrayList<>();

    LocalSnapshotMetadata(Artifact artifact, Date timestamp) {
        super(createMetadata(artifact), (Path) null, timestamp);
    }

    LocalSnapshotMetadata(Metadata metadata, Path path, Date timestamp) {
        super(metadata, path, timestamp);
    }

    private static Metadata createMetadata(Artifact artifact) {

    private final Path path;

    protected final Date timestamp;

    private boolean merged;

    @Deprecated
    protected MavenMetadata(Metadata metadata, File file, Date timestamp) {
        this(metadata, file != null ? file.toPath() : null, timestamp);
    }

    protected MavenMetadata(Metadata metadata, Path path, Date timestamp) {
        this.metadata = metadata;
        this.path = path;

        }
    }

    public boolean getIfNewer(String resourceName, File destination, long timestamp)
            throws TransferFailedException, ResourceDoesNotExistException, AuthorizationException {
        if (!insideGet) {
            addTransfer("getIfNewer " + resourceName);
        }
        return super.getIfNewer(resourceName, destination, timestamp);
    }

    public void addTransferListener(TransferListener listener) {

        this.buildNumber = buildNumber;
    }

    private RemoteSnapshotMetadata(Metadata metadata, Path path, Date timestamp, Integer buildNumber) {
        super(metadata, path, timestamp);
        this.buildNumber = buildNumber;
    }

    @Deprecated
    @Override
    public MavenMetadata setFile(File file) {
        return new RemoteSnapshotMetadata(metadata, file.toPath(), timestamp, buildNumber);
    }

      <fields>
        <field>
          <name>uniqueVersion</name>
          <description>Whether to assign snapshots a unique version comprised of the timestamp and
            build number, or to use the same version each time</description>
          <type>boolean</type>
          <defaultValue>true</defaultValue>
          <version>4.0.0+</version>
        </field>