conn.go
func (c *Conn) sendResponse(id string, result interface{}, err *ResError) error {
	return c.send(response{ID: id, Result: result, Error: err})
}
func (c *Conn) sendResponse(id string, result interface{}, err *ResError) error {
	return c.send(response{ID: id, Result: result, Error: err})
}
// SendResponse sends a JSON-RPC response message through the connection.