public static function get_calling_script_file( $offset = 0 ) {
		$callers = array();
		$backtrace = debug_backtrace();
		foreach ( $backtrace as $trace ) {
			if ( array_key_exists('file', $trace) && $trace['file'] != __FILE__ ) {
				$callers[] = $trace['file'];
			}
		}		
		$callers = array_unique($callers);
		$callers = array_values($callers);
		return $callers[$offset];
	}