code: public boolean compare(Object object) {
          if (!(object instanceof IChemObject)) {
              return false;
          }
          ChemObject chemObj = (ChemObject) object;
          return Objects.equal(identifier, chemObj.identifier);
      }
docs: Compares a IChemObject with this IChemObject.
  
  @param  object  Object of type AtomType
  @return         true if the atom types are equal