code: private boolean getIfBondIsNotRotatable(IAtomContainer mol, IBond bond, IAtomContainer detected) {
          boolean isBondNotRotatable = false;
          int counter = 0;
          IAtom atom0 = bond.getBegin();
          IAtom atom1 = bond.getEnd();
          if (detected != null) {
              if (detected.contains(bond)) counter += 1;
          }
          if (atom0.getFlag(CDKConstants.ISINRING)) {
              if (atom1.getFlag(CDKConstants.ISINRING)) {
                  counter += 1;
              } else {
                  if (atom1.getSymbol().equals("H"))
                      counter += 1;
                  else
                      counter += 0;
              }
          }
          if (atom0.getSymbol().equals("N") && atom1.getSymbol().equals("C")) {
              if (getIfACarbonIsDoubleBondedToAnOxygen(mol, atom1)) counter += 1;
          }
          if (atom0.getSymbol().equals("C") && atom1.getSymbol().equals("N")) {
              if (getIfACarbonIsDoubleBondedToAnOxygen(mol, atom0)) counter += 1;
          }
          if (counter > 0) isBondNotRotatable = true;
          return isBondNotRotatable;
      }
docs: Others definitions