public function saveUserGravatar(User $user, $size = 500)
{
$emailHash = md5(strtolower(trim($user->email)));
$url = 'https://www.gravatar.com/avatar/' . $emailHash . '?s=' . $size . '&d=identicon';
$imageName = str_replace(' ', '-', $user->name . '-gravatar.png');
$image = $this->saveNewFromUrl($url, 'user', $imageName);
$image->created_by = $user->id;
$image->updated_by = $user->id;
$image->save();
return $image;
}