code: public function getPhotoUrl($size = 200)
      {
          $storage = $this->storageObject;
          if ($storage) {
              // yay! we have a local image
              return Url::to(['/object/photo', 'id' => $this->owner->primaryKey, 'size' =>  $size]);
          }
          if ($this->owner->photoEmail) {
              $gravatar = new Gravatar();
              if ($gravatar->test($this->owner->photoEmail)) {
                  $gravatar->setAvatarSize($size);
  
                  return $gravatar->get($this->owner->photoEmail);
              }
          }
  
          return false;
      }
docs: Get photo url.
  
  @param integer $size [[@doctodo param_description:size]] [optional]
  
  @return [[@doctodo return_type:getPhotoUrl]] [[@doctodo return_description:getPhotoUrl]]