protected static function _call($callable, $request, $params) {
		$params = compact('callable', 'request', 'params');
		return Filters::run(get_called_class(), __FUNCTION__, $params, function($params) {
			if (is_callable($callable = $params['callable'])) {
				$request = $params['request'];
				$params = $params['params'];

				if (!method_exists($callable, $params['action'])) {
					array_unshift($params['args'], $request->params['action']);
					$params['action'] = 'run';
				}
				$isHelp = (
					!empty($params['help']) || !empty($params['h']) ||
					!method_exists($callable, $params['action'])
				);
				if ($isHelp) {
					$params['action'] = '_help';
				}
				return $callable($params['action'], $params['args']);
			}
			throw new UnexpectedValueException("Callable `{$callable}` is actually not callable.");
		});
	}