code: @Override
  	public boolean hasAminoAtoms(){
  		// if this method call is performed too often, it should become a
  		// private method and provide a flag for Group object ...
  
  		return hasAtom(StructureTools.CA_ATOM_NAME) &&
  				hasAtom(StructureTools.C_ATOM_NAME) &&
  				hasAtom(StructureTools.N_ATOM_NAME) &&
  				hasAtom(StructureTools.O_ATOM_NAME);
  
  	}
docs: {@inheritDoc}