code: func (t *SimpleChaincode) respond(stub shim.ChaincodeStubInterface, args []string) pb.Response {
  	if len(args) != 3 {
  		return shim.Error("expected three arguments")
  	}
  
  	status, err := strconv.ParseInt(args[0], 10, 32)
  	if err != nil {
  		return shim.Error(err.Error())
  	}
  	message := args[1]
  	payload := []byte(args[2])
  
  	return pb.Response{
  		Status:  int32(status),
  		Message: message,
  		Payload: payload,
  	}
  }
docs: // respond simply generates a response payload from the args