code: public static String buildFilterID(String application_name, FilterType filter_type, String filter_name) {
          return application_name + ":" + filter_name + ":" + filter_type.toString();
      }
docs: builds the unique filter_id key
  @param application_name
  @param filter_type
  @param filter_name
  @return key is application_name:filter_name:filter_type