src/GuzzleHelper.php
public function post($url, $data = array())
    {
        $client = $this->getClient();

        return $client->request('POST', $url, array('form_params' => $data));
    }
public function post($url, $data = array())
    {
        $client = $this->getClient();

        return $client->request('POST', $url, array('form_params' => $data));
    }
Perform POST request

@param string url
@param array data

@return string content