* Double#valueOf}.
   */
  private static @Nullable Double referenceTryParse(String input) {
    if (input.trim().length() < input.length()) {
      return null;
    }
    try {
      return Double.valueOf(input);
    } catch (NumberFormatException e) {
      return null;
    }
  }

  @GwtIncompatible // Doubles.tryParse
  private static void checkTryParse(String input) {

    // Parse the address, and make sure the length/version is correct.
    Scope scope = parseScope ? new Scope() : null;
    byte[] addr = ipStringToBytes(ipString, scope);
    if (addr == null || addr.length != expectBytes) {
      return null;
    }

    return bytesToInetAddress(addr, (scope != null) ? scope.scope : null);
  }

  /**

    // to propagate immediately.
    Exception exception = null;
    for (BaseStream<?, ?> stream : toClose) {
      try {
        stream.close();
      } catch (Exception e) { // sneaky checked exception
        if (exception == null) {
          exception = e;
        } else {
          exception.addSuppressed(e);
        }
      }
    }
    if (exception != null) {

      return true;
    }

    /*
     * Some operating systems may return zero as the length for files denoting system-dependent
     * entities such as devices or pipes, in which case we must fall back on comparing the bytes
     * directly.
     */
    long len1 = file1.length();
    long len2 = file2.length();
    if (len1 != 0 && len2 != 0 && len1 != len2) {
      return false;
    }

                null, // effectiveModel is null
                null, // rawModel is null
                createMockModel("com.example", "test-project", "1.0.0") // fileModel is available
                );

        String projectId = (String) extractProjectIdMethod.invoke(null, mockResult);

        assertNotNull(projectId, "Project ID should not be null");
        assertEquals(

      return null;
    }
    long accum = -digit;

    long cap = Long.MIN_VALUE / radix;

    while (index < string.length()) {
      digit = AsciiDigits.digit(string.charAt(index++));
      if (digit < 0 || digit >= radix || accum < cap) {
        return null;
      }
      accum *= radix;
      if (accum < Long.MIN_VALUE + digit) {
        return null;
      }
      accum -= digit;

                }
            """
        ) {
            assertHasErrors(
                "Method com.example.Source.foo(): From non-null returning to null-unmarked returning breaking change.",
                "Method com.example.Source.baz(): From non-null returning to null-unmarked returning breaking change.",
            )
            assertHasNoWarning()

    }
    // ------------------------------------------------------------------------
    public MetadataGraphVertex addVertex(ArtifactMetadata md) {
        if (md == null) {
            return null;
        }

        checkVertices();

        MetadataGraphVertex v = findVertex(md);
        if (v != null) {
            return v;
        }

        v = new MetadataGraphVertex(md);

        return treeRoot == null ? null : new MetadataGraph(treeRoot);
    }
    // ----------------------------------------------------------------------------
    public MetadataGraph getGraph(ArtifactScopeEnum scope)
            throws MetadataResolutionException, GraphConflictResolutionException {
        if (treeRoot == null) {
            return null;
        }

        if (conflictResolver == null) {

        this.groupId = (groupId != null && !groupId.isEmpty()) ? groupId : null;
        this.artifactId = (artifactId != null && !artifactId.isEmpty()) ? artifactId : null;
        this.classifier = (classifier != null && !classifier.isEmpty()) ? classifier : null;
        this.extension = (extension != null && !extension.isEmpty()) ? extension : null;