code: def unpack_rsp(cls, rsp_pb):
          
          if rsp_pb.retType != RET_OK:
              return RET_ERROR, rsp_pb.retMsg, None
  
          if rsp_pb.HasField('retMsg'):
              return RET_OK, rsp_pb.retMsg, None
          return RET_OK, "", None
docs: Convert from PLS response to user response