for (CharSource source : sources) {
        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()) {

      for (CharSource source : sources) {
        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()) {

    }

    @Test
    void testGetInputStream() throws Exception {
        URL txtFile = new File("target/test-classes/source.txt").toURI().toURL();
        UrlSource source = new UrlSource(txtFile);
        try (InputStream is = source.getInputStream();
                Scanner scanner = new Scanner(is)) {
            assertEquals("Hello World!", scanner.nextLine());
        }
    }

    @Test

	// S3 extensions
	AmzCopySourceIfModifiedSince   = "x-amz-copy-source-if-modified-since"
	AmzCopySourceIfUnmodifiedSince = "x-amz-copy-source-if-unmodified-since"

	AmzCopySourceIfNoneMatch = "x-amz-copy-source-if-none-match"
	AmzCopySourceIfMatch     = "x-amz-copy-source-if-match"

	AmzCopySource                 = "X-Amz-Copy-Source"
	AmzCopySourceVersionID        = "X-Amz-Copy-Source-Version-Id"

@Experimental
public final class Sources {

    private Sources() {}

    /**
     * Creates a new source for the specified path.
     *
     * @param path the path to the file
     * @return a new Source instance
     * @throws NullPointerException if path is null
     */
    @Nonnull
    public static Source fromPath(@Nonnull Path path) {
        return new PathSource(requireNonNull(path, "path"));
    }

    /**

        this.configuration = null;
    }

    public MojoExecution(MojoDescriptor mojoDescriptor, String executionId, Source source) {
        this.mojoDescriptor = mojoDescriptor;
        this.executionId = executionId;
        this.configuration = null;
        this.source = source;
    }

    public MojoExecution(MojoDescriptor mojoDescriptor, String executionId) {
        this.mojoDescriptor = mojoDescriptor;

            Severity severity,
            Version version,
            String source,
            int lineNumber,
            int columnNumber,
            String modelId,
            Exception exception) {
        this.message = message;
        this.severity = (severity != null) ? severity : Severity.ERROR;
        this.source = (source != null) ? source : "";
        this.lineNumber = lineNumber;

    /**
     * The next messages will be bound to this source. When calling this method again, previous messages keep
     * their source, but the next messages will use the new source.
     *
     * @param source a source
     */
    void setSource(String source);

    /**
     *
     * @return the collected Problems, never {@code null}
     */

	dm.Lock(id, source)
	time.Sleep(time.Duration(10+(rand.Float32()*50)) * time.Millisecond)
	dm.Unlock(t.Context())

	dm.Lock(id, source)
	time.Sleep(time.Duration(10+(rand.Float32()*50)) * time.Millisecond)
	dm.Unlock(t.Context())

	dm.Lock(id, source)
	time.Sleep(time.Duration(10+(rand.Float32()*50)) * time.Millisecond)
	dm.Unlock(t.Context())

	dm.Lock(id, source)
	time.Sleep(time.Duration(10+(rand.Float32()*50)) * time.Millisecond)

      return responseBody.contentLength();
    }

    @Override public BufferedSource source() {
      if (bufferedSource == null) {
        bufferedSource = Okio.buffer(source(responseBody.source()));
      }
      return bufferedSource;
    }

    private Source source(Source source) {
      return new ForwardingSource(source) {
        long totalBytesRead = 0L;