public function testLock()
{
$lock = new LockHandler('contao:filesync');
$lock->lock();
$command = new FilesyncCommand('contao:filesync');
$command->setFramework($this->mockContaoFramework());
$tester = new CommandTester($command);
$code = $tester->execute([]);
$this->assertEquals(1, $code);
$this->assertContains('The command is already running in another process.', $tester->getDisplay());
$lock->release();
}