/**
  * @return MediaType|null
  */
 public function classify($filename)
 {
     $file = new File($filename);
     $mimetype = $file->getMimeType();
     $mediaType = null;
     if ($mimetype) {
         $mediaType = $this->mediaTypes->lookup($mimetype);
     }
     if (!$mediaType) {
         $mediaType = $this->mediaTypes->get($this->fallbackMediaType);
     }
     return $mediaType;
 }
 public function testGetReturnsNullOnNotFound()
 {
     $this->assertNull($this->mediatypes->get('image:jpg'));
 }