public function testFilterWithEmptyString()
 {
     $name = 'ö ö ö.jpg';
     $filter = new FileNameFilter();
     $filter->setTransliterator(new Transliterator());
     $result = $filter->filter($name);
     $this->assertFalse(empty($result));
     $this->assertStringEndsWith('.jpg', $result);
     $this->assertGreaterThan(strlen('.jpg'), strlen($result));
 }