/**
* created singleton instance of this class. see explanation in constructor method
*
* @error 14002
* @see Xapp_Rpc_Gateway::__construct()
* @param null|string|Xapp_Rpc_Server $server expects on of the above explained values
* @param null|array|object $options expects optional options
* @param null|string $conf expects file pointer or string of gateway config
* @return Xapp_Rpc_Gateway
*/
public static function instance($server = null, $options = null, $conf = null)
{
if (self::$_instance === null) {
self::$_instance = new self($server, $options, $conf);
}
return self::$_instance;
}
