public String toString() {
        return "[" + (md == null ? "no metadata" : md.toString()) + "]";
    }

    // ---------------------------------------------------------------------
    private static int compareStrings(String s1, String s2) {
        if (s1 == null && s2 == null) {
            return 0;
        }

        if (s1 == null /* && s2 != null */) {
            return -1;
        }

        if (

    try {
      assertNull(
          "remove(null) should return null or throw NullPointerException", getMap().remove(null));
    } catch (NullPointerException tolerated) {
    }
    expectUnchanged();
  }

  @MapFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_KEY_QUERIES})
  public void testRemove_nullSupportedMissing() {
    assertNull("remove(null) should return null", getMap().remove(null));
    expectUnchanged();
  }

    }

    @Override
    public Set<Artifact> createArtifacts(MavenProject project) throws InvalidDependencyVersionException {
        return createArtifacts(artifactFactory, project.getDependencies(), null, null, project);
    }

    public static Set<Artifact> createArtifacts(
            ArtifactFactory artifactFactory,
            List<Dependency> dependencies,
            String inheritedScope,

                coreExtension.setGroupId(interpolatedTrimmed(parser.nextText(), "groupId"));
            } else if (checkFieldWithDuplicate(parser, "artifactId", null, parsed)) {
                coreExtension.setArtifactId(interpolatedTrimmed(parser.nextText(), "artifactId"));
            } else if (checkFieldWithDuplicate(parser, "version", null, parsed)) {

    return (javaUtilOptional == null) ? null : fromNullable(javaUtilOptional.orElse(null));
  }

  /**
   * Returns the equivalent {@code java.util.Optional} value to the given {@code
   * com.google.common.base.Optional}, or {@code null} if the argument is null.
   *
   * <p>If {@code googleOptional} is known to be non-null, use {@code googleOptional.toJavaUtil()}
   * instead.
   *

         *
         * @param path the filesystem path to the source content
         * @throws NullPointerException if path is null
         */
        PathSource(Path path) {
            this(path, null);
        }

        /**
         * Constructs a new PathSource with the specified path and location.
         *

                    return e;
                }
            }

            return null;
        }

        @SuppressWarnings({"unchecked", "checkstyle:methodlength"})
        private void traverseObjectWithParents(Class<?> cls, Object target) throws ModelInterpolationException {
            if (cls == null) {
                return;
            }

            if (cls.isArray()) {

     */
    public StringSource(CharSequence content) {
        this(content, null);
    }

    /**
     * Creates a new source backed by the specified string.
     *
     * @param content The String representation, may be empty or {@code null}.
     * @param location The location to report for this use, may be {@code null}.
     */

    Set<CombinedInterface> getSetProp() { return null; }

    Map<CombinedInterface, JavaClassWithParameterizedTypes> getMapProp() { return null; }

    List<?> getWildcardProp() { return null; }

    List<? extends CombinedInterface> getUpperBoundProp() { return null; }

    List<? super CombinedInterface> getLowerBoundProp() { return null; }

     *
     * @param groupId the group identifier, or {@code null} is unspecified
     * @param artifactId the artifact identifier, or {@code null} is unspecified
     * @param version the artifact version, or {@code null} is unspecified
     * @param classifier the artifact classifier, or {@code null} is unspecified
     * @param extension the artifact extension, or {@code null} is unspecified