/**
* Returns an instance of Ht_Mail
*
* Singleton pattern implementation
*
* @return Ht_Mail Provides a fluent interface
*/
public static function getInstance($host = "", $port = null, $config = array())
{
if (null === self::$_instance) {
self::$_instance = new self($host, $port, $config);
}
return self::$_instance;
}