private function action(ActionHandler $handler)
		{
			try {
				$presenter = $this -> presenterFactory
					-> createPresenter($handler -> presenter, $handler -> args);
			}
			catch (\Exception $e) {
				throw new InternalServerErrorException($e -> getMessage());
			}

// Call action/execute
			if (!method_exists($presenter, $handler -> action)) {
				throw new BadFunctionCallException(sprintf("Can not call `%s`.", $handler -> action));
			}
			$presenter -> startup();
			call_user_func_array([$presenter, $handler -> action], []);
//
			$response = $this -> httpResponse;
			if (!$response -> isRedirect() && empty($response -> contents)) {
				$response -> contents = $presenter -> render();
			}
			unset($presenter);
		}