code: @Override
      public IRingSet getRings(IAtom atom) {
          IRingSet rings = new RingSet();
          IRing ring;
          for (int i = 0; i < getAtomContainerCount(); i++) {
              ring = (Ring) getAtomContainer(i);
              if (ring.contains(atom)) {
                  rings.addAtomContainer(ring);
              }
          }
          return rings;
      }
docs: Returns a vector of all rings that this atom is part of.
  
  @param   atom  The atom to be checked
  @return   A vector of all rings that this bond is part of