/**
  * Updates the specified issue attachment.
  *
  * @param AttachmentRequest $request
  * @param int|string        $issueId
  * @param string            $fileUuid
  *
  * @return \Illuminate\Http\RedirectResponse
  */
 public function update(AttachmentRequest $request, $issueId, $fileUuid)
 {
     $issue = $this->issue->findOrFail($issueId);
     $this->authorize($issue);
     $file = $issue->findFile($fileUuid);
     if ($request->persist($file)) {
         flash()->success('Success!', 'Successfully updated attachment.');
         return redirect()->route('issues.attachments.show', [$issueId, $fileUuid]);
     }
     flash()->error('Error!', 'There was an issue updating this attachment. Please try again.');
     return redirect()->route('issues.attachments.edit', [$issueId, $fileUuid]);
 }