* an element in the set. For example, {@code contains} returns {@code false} when passed an
   * object that equals a set member, but isn't the same instance. This behavior is similar to the
   * way {@code IdentityHashMap} handles key lookups.
   *
   * @since 8.0
   */
  public static <E extends @Nullable Object> Set<E> newIdentityHashSet() {
    return Collections.newSetFromMap(Maps.<E, Boolean>newIdentityHashMap());
  }

  /**

   * element is found, {@code defaultValue} will be returned from this method and the iterator will
   * be left exhausted: its {@code hasNext()} method will return {@code false}. Note that this can
   * usually be handled more naturally using {@code tryFind(iterator, predicate).or(defaultValue)}.
   *
   * @since 7.0
   */
  // For discussion of this signature, see the corresponding overload of *Iterables*.find.
  @CheckForNull

            String sourceHint,
            InputLocationTracker tracker,
            ModelBuilderRequest request) {
        if (string == null) {
            // NOTE: The check for missing plugin versions is handled directly by the model builder
            return true;
        }

        Severity errOn30 = getSeverity(request, ModelBuilderRequest.VALIDATION_LEVEL_MAVEN_3_0);