code: public String getInputUniqueGroupId(String inputVirtualRealm) {
          // initialize the return value
          String returnValue = getInputMapping(inputVirtualRealm, Service.CONFIG_DO_UNIQUE_GROUP_ID_MAPPING,
                                               INPUT_UNIQUE_GROUP_ID_DEFAULT);
          return returnValue;
      }
docs: Get the input unique group ID mapping for the UserRegistry.
  
  @param inputVirtualRealm Virtual realm to find the mappings.
  
  @return The input unique group ID property.
  
  @pre inputVirtualRealm != null
  @pre inputVirtualRealm != ""
  @post $return != ""
  @post $return != null