code: private static Map<String, String> generateMapChangeIds(List<String> newIDs) {
      Map<String, String> mapIds = new HashMap<String, String>();
      List<String> oldIds = HELM2NotationUtils.helm2notation.getPolymerAndGroupingIDs();
  
      Map<String, String> mapOldIds = new HashMap<String, String>();
      for (String oldID : oldIds) {
        mapOldIds.put(oldID, "");
      }
      for (String newId : newIDs) {
        if (mapOldIds.containsKey(newId)) {
          int i = 1;
          String type = newId.split("\\d")[0];
  
          while (mapOldIds.containsKey(type + i)) {
            i++;
          }
          mapIds.put(newId, type + i);
        }
      }
  
      return mapIds;
  
    }
docs: method to generate a Map of old ids with the new ids
  
  @param newIDs
  @return {@code Map<String, String>} containing the old ids with the new ids