/**
  * Add content type header from request if not defined.
  *
  * @param Request $request
  */
 private function fixContentType(Request $request)
 {
     // Add content type from request if not defined.
     if (false === $this->headers->has('Content-Type') && true === $request->getHeaderBag()->has('Accept')) {
         /**
          * @var AcceptHeader $acceptHeader
          */
         $acceptHeader = $request->getHeaderBag()->first('Accept');
         // get first accept content type=
         $this->setContentType($acceptHeader->first()->getValue());
     }
 }