public static function enabled($feature = null) {
		if (!$feature) {
			return extension_loaded('pdo_sqlite');
		}
		$features = [
			'arrays' => false,
			'transactions' => false,
			'booleans' => true,
			'schema' => true,
			'relationships' => true,
			'sources' => true
		];
		return isset($features[$feature]) ? $features[$feature] : null;
	}