public function testGetDate()
 {
     $it = new DirectoryIterator('tests/test-files/logs');
     $it->setFilenameFormat(new FilenameFormat('payment.{Ymd}.log'));
     foreach ($it as $item) {
         if ($it->isFile()) {
             $this->assertEquals(\DateTime::createFromFormat('Ymd', '20160324'), $item->getFilenameDate());
             return;
         }
     }
 }