/**
* Runs the current application.
*
* @param InputInterface $input An Input instance
* @param OutputInterface $output An Output instance
*
* @return integer 0 if everything went fine, or an error code
*/
public function doRun(InputInterface $input, OutputInterface $output)
{
if (true === $input->hasParameterOption(array('--shell', '-s'))) {
$shell = new Shell($this);
$shell->run();
return 0;
}
return parent::doRun($input, $output);
}