var ErrClientClosed = errors.New("rest client is closed")

// Call - make a REST call with context.
func (c *Client) Call(ctx context.Context, method string, values url.Values, body io.Reader, length int64) (reply io.ReadCloser, err error) {
	switch atomic.LoadInt32(&c.connected) {
	case closed:
		// client closed, this is usually a manual process
		// so return a local error as client is closed