/**
 * Factory methods for creating different types of sources.
 * <p>
 * This class provides specialized source implementations for different use cases:
 * <ul>
 *   <li>Path sources - simple access to file content</li>
 *   <li>Build sources - POM files being actively built by Maven</li>
 *   <li>Resolved sources - POMs resolved from repositories</li>
 * </ul>
 *
 * @since 4.0.0
 */
@Experimental

 * @see org.apache.maven.api.services.ProjectBuilder#build(Session, Source)
 */
@Experimental
public interface Source {
    /**
     * Provides access to the file backing this source, if available.
     * Not all sources are backed by files - for example, in-memory sources
     * or database-backed sources will return null.
     *
     * @return the underlying {@code Path} if this source is file-backed,

        if (!source.isEmpty()) {
          return false;
        }
      }
      return true;
    }

    @Override
    public Optional<Long> lengthIfKnown() {
      long result = 0L;
      for (CharSource source : sources) {
        Optional<Long> lengthIfKnown = source.lengthIfKnown();
        if (!lengthIfKnown.isPresent()) {
          return Optional.absent();
        }

        if (!source.isEmpty()) {
          return false;
        }
      }
      return true;
    }

    @Override
    public Optional<Long> lengthIfKnown() {
      long result = 0L;
      for (CharSource source : sources) {
        Optional<Long> lengthIfKnown = source.lengthIfKnown();
        if (!lengthIfKnown.isPresent()) {
          return Optional.absent();
        }

        Path path = Paths.get("/tmp");
        Source source = Sources.fromPath(path);

        assertNotNull(source);
        assertInstanceOf(Sources.PathSource.class, source);
        assertEquals(path.normalize(), source.getPath());
    }

    @Test
    void testBuildSource() {
        Path path = Paths.get("/tmp");
        ModelSource source = Sources.buildSource(path);

        assertNotNull(source);

 *   <li>Resolved sources: Used for artifacts that have been resolved by Maven from repositories
 *       (using groupId:artifactId:version coordinates) and downloaded to the local repository.
 *       These sources do not support resolving other sources.</li>
 * </ul>
 *
 * @since 4.0.0
 * @see Source
 */
public interface ModelSource extends Source {

    /**

   *
   * @param sources the sources to concatenate
   * @return a {@code ByteSource} containing the concatenated data
   * @throws NullPointerException if any of {@code sources} is {@code null}
   * @since 15.0
   */
  public static ByteSource concat(ByteSource... sources) {
    return concat(ImmutableList.copyOf(sources));
  }

  /**

        ModelSource source = Sources.resolvedSource(path, modelId);

        assertNotNull(source);
        assertEquals(modelId, source.getModelId(), "Resolved source should return the provided modelId");
        assertNull(source.getPath(), "Resolved sources should return null for getPath()");
        assertEquals(path.toString(), source.getLocation());
    }

    @Test

    @Override
    public void importManagement(
            Model target,
            List<? extends DependencyManagement> sources,
            ModelBuildingRequest request,
            ModelProblemCollector problems) {
        if (sources != null && !sources.isEmpty()) {
            Map<String, Dependency> dependencies = new LinkedHashMap<>();

							<directory>${packaging.fess.lib.dir}/classes</directory>
							<sources>
								<source>
									<location>${project.build.directory}/tomcat-lib</location>
								</source>
							</sources>
						</mapping>
						<mapping>
							<directory>${packaging.fess.lib.dir}/classes/org/codelibs/fess</directory>
							<sources>
								<source>