code: public static int markRingAtomsAndBonds(IAtomContainer mol) {
          EdgeToBondMap bonds = EdgeToBondMap.withSpaceFor(mol);
          return markRingAtomsAndBonds(mol, GraphUtil.toAdjList(mol, bonds), bonds);
      }
docs: Find and mark all cyclic atoms and bonds in the provided molecule.
  
  @param mol molecule
  @see IBond#isInRing()
  @see IAtom#isInRing()
  @return Number of rings found (circuit rank)
  @see <a href="https://en.wikipedia.org/wiki/Circuit_rank">Circuit Rank</a>