code: private static void checkExistenceOfPolymerID(String str, List<String> listPolymerIDs) throws PolymerIDsException {
  		if (!(listPolymerIDs.contains(str))) {
  			LOG.info("Polymer Id does not exist");
  			throw new PolymerIDsException("Polymer ID does not exist");
  		}
  	}
docs: method to check if the given polymer id exists in the given list of
  polymer ids
  
  @param str
  polymer id
  @param listPolymerIDs
  List of polymer ids
  @return true if the polymer id exists, false otherwise
  @throws PolymerIDsException
  if the polymer id does not exist