Symfony 代码执行 Command

namespace App\Command;
use Command;
class TestCommand extend Command
{
    protected function execute(InputInterface $input, OutputInterface $output)
    {
        $command = $this->getApplication()->find('demo:greet');
        $arguments = array(
            'command' => 'demo:greet',
            'name'    => 'Fabien',
            '--yell'  => true,
        );
        $input = new ArrayInput($arguments);
        $returnCode = $command->run($input, $output);
        // ...
    }
}