private function invalidBody()
{
throw new \InvalidArgumentException('Passing in the "body" request ' . 'option as an array to send a POST request has been deprecated. ' . 'Please use the "form_params" request option to send a ' . 'application/x-www-form-urlencoded request, or a the "multipart" ' . 'request option to send a multipart/form-data request.');
}