jsonrpc2.go
func (c *Conn) ReplyWithError(ctx context.Context, id ID, respErr *Error) error {
	_, err := c.send(ctx, &anyMessage{response: &Response{ID: id, Error: respErr}}, false)
	return err
}
func (c *Conn) ReplyWithError(ctx context.Context, id ID, respErr *Error) error {
	_, err := c.send(ctx, &anyMessage{response: &Response{ID: id, Error: respErr}}, false)
	return err
}
// ReplyWithError sends a response with an error.