code: def append(self, payload):
          
          if self.objType.setInParentPayload:
              print('Error, {} is not elibible to addition, but only set'
                    .format(self.objName))
              return False
          ret = self.api.create("{}/{}/{}".format(self.parentObjName,
                                                  self.parentKey,
                                                  self.objNameSet),
                                self.getPayloadStruct(payload))
          return ret
docs: Function __iadd__
  
          @param payload: The payload corresponding to the object to add
          @return RETURN: A ForemanItem