code: func (c *Client) Post(endpoint string, req interface{}, resp interface{}) error {
  	return c.Result(c.NewJsonRequest(POST, endpoint, req), resp)
  }
docs: // Post issues a POST request to the specified endpoint with the req payload
  // marshaled to JSON and parses the response into resp. It will return an error
  // if it failed to send the request, a *RestError if the response wasn't a 2xx
  // status code, or an error from package json's Decode.