code: @Override
      public void addAtom(IPDBAtom oAtom, IMonomer oMonomer, IStrand oStrand) {
          super.addAtom(oAtom, oMonomer, oStrand);
          if (!sequentialListOfMonomers.contains(oMonomer.getMonomerName()))
              sequentialListOfMonomers.add(oMonomer.getMonomerName());
      }
docs: Adds the IPDBAtom oAtom to a specified Monomer of a specified Strand.
  Additionally, it keeps record of the iCode.
  
  @param oAtom  The IPDBAtom to add
  @param oMonomer  The monomer the atom belongs to