code: public static boolean checkIfAllLigandsAreDifferent(ILigand[] ligands) {
          for (int i = 0; i < (ligands.length - 1); i++) {
              if (cipRule.compare(ligands[i], ligands[i + 1]) == 0) return false;
          }
          return true;
      }
docs: Checks if each next {@link ILigand} is different from the previous
  one according to the {@link CIPLigandRule}. It assumes that the input
  is sorted based on that rule.
  
  @param ligands array of {@link ILigand} to check
  @return true, if all ligands are different