docs: public static SiblingCounter create( final CachedNode node,
                                           final NodeCache cache ) {
          assert node != null;
          assert cache != null;
          return new SiblingCounter() {
              @Override
              public int countSiblingsNamed( Name childName ) {
                  return node.getChildReferences(cache).getChildCount(childName);
              }
          };
      }