code: private static CyclicVertexSearch makeSearcher(int[][] graph) {
  
          if (graph == null) throw new NullPointerException("graph[][] must not be null");
  
          // if the molecule has 64 or less atoms we can use single 64 bit long
          // values to represent our sets of vertices
          if (graph.length <= 64) {
              return new RegularCyclicVertexSearch(graph);
          } else {
              return new JumboCyclicVertexSearch(graph);
          }
      }
docs: Utility method making a new {@link CyclicVertexSearch} during
  construction.
  
  @param graph non-null graph
  @return a new cyclic vertex search for the given graph
  @throws NullPointerException if the graph was null