code: public static boolean isAnonymousNodeIRI(String uri) {
          return uri != null && uri.startsWith(PREFIX) && uri.contains(NODE_ID_PREFIX);
      }
docs: Tests whether supplied IRI was generated by this parser in order to label
  an anonymous node.
  
  @param uri
  the IRI
  @return {@code true} if the IRI was generated by this parser to label an
  anonymous node