public static function remember( $key, $expires, Closure $closure )
	{
		$cache = self::instance();
		if ( $cache ) {
			if ( $cache->isExisting( $key ) ) {
				return $cache->get( $key );
			} else if ( $closure != null ) {
				$value = $closure();
				$cache->set( $key, $value, $expires * 60 );
				return $value;
			}
		}
		return $closure();
	}