/**
* Set proxy information
*
* @param string $host Proxy hostname and port (localhost:1234)
* @param string $user Proxy username
* @param string $pass Proxy password
* @param constant $type CURL proxy type
* @return void
*/
public static function setProxy($host, $user = null, $pass = null, $type = CURLPROXY_SOCKS5)
{
self::$proxy = array('host' => $host, 'type' => $type, 'user' => null, 'pass' => 'null');
}