*
     * @return The of the artifact in bytes or a negative value if unknown.
     */
    long getContentLength();

    /**
     * Gets the timestamp when the transfer of this artifact was started.
     *
     * @return The timestamp when the transfer of this artifact was started.
     */
    long getTransferStartTime();

@Named
@Singleton
public class DefaultModelVersionParser implements ModelVersionParser {
    private static final String SNAPSHOT = "SNAPSHOT";
    private static final Pattern SNAPSHOT_TIMESTAMP = Pattern.compile("^(.*-)?([0-9]{8}\\.[0-9]{6}-[0-9]+)$");
    private final VersionScheme versionScheme;

    @Inject
    public DefaultModelVersionParser(VersionScheme versionScheme) {

            this.startTime = startTime;
            this.properties = properties;
        }

        @Override
        public Object getValue(String expression) {
            if ("build.timestamp".equals(expression) || "maven.build.timestamp".equals(expression)) {
                return new MavenBuildTimestamp(startTime, properties).formattedTimestamp();
            }
            return null;
        }
    }

        String timestampFormat = DEFAULT_BUILD_TIMESTAMP_FORMAT;

        Properties modelProperties = model.getProperties();
        if (modelProperties != null) {
            timestampFormat = modelProperties.getProperty(BUILD_TIMESTAMP_FORMAT_PROPERTY, timestampFormat);
        }

    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 static class VersionInfo {

        String timestamp;

        String version;

        ArtifactRepository repository;

        VersionInfo(String timestamp, String version, ArtifactRepository repository) {
            this.timestamp = (timestamp != null) ? timestamp : "";
            this.version = version;
            this.repository = repository;
        }

    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;

 */
class LocalSnapshotMetadataGenerator implements MetadataGenerator {

    private final Map<Object, LocalSnapshotMetadata> snapshots;

    private final Date timestamp;

    LocalSnapshotMetadataGenerator(RepositorySystemSession session, InstallRequest request) {
        timestamp = (Date) ConfigUtils.getObject(session, new Date(), "maven.startTime");

        snapshots = new LinkedHashMap<>();
    }

    @Override

        super(false);
        this.startTime = startTime;
        this.format = format;
    }

    public Object getValue(String expression) {
        if ("build.timestamp".equals(expression) || "maven.build.timestamp".equals(expression)) {
            if (formattedDate == null && startTime != null) {
                formattedDate = new SimpleDateFormat(format).format(startTime);
            }

      <description>Snapshot data for the last artifact corresponding to the SNAPSHOT base version</description>
      <fields>
        <field>
          <name>timestamp</name>
          <version>1.0.0+</version>
          <description>The timestamp when this version was deployed. The timestamp is expressed using UTC in the format yyyyMMdd.HHmmss.</description>
          <type>String</type>
        </field>
        <field>