public function init($input, $output, $appName = null, $appVersion = null)
{
// If we were not provided a container, then create one
if (!Robo::hasContainer()) {
Robo::createDefaultContainer($input, $output, $appName, $appVersion);
// Automatically register a shutdown function and
// an error handler when we provide the container.
$this->installRoboHandlers();
}
$app = Robo::application();
$this->registerRoboFileCommands($app);
return $app;
}