public function testGetBlacklistFilter()
 {
     mkdir('sub');
     touch('alpha.php');
     touch('beta.php');
     touch('sub/beta.php');
     $alpha = new SplFileInfo('alpha.php');
     $beta = new SplFileInfo('beta.php');
     $sub = new SplFileInfo('sub/alpha.php');
     $this->setConfig(array('blacklist' => 'beta.php'));
     $callable = $this->config->getBlacklistFilter();
     $this->assertNull($callable($alpha));
     $this->assertFalse($callable($beta));
     $this->assertNull($callable($sub));
 }