/**
  * Generate the Pet Basket of a user
  * @param type $userId        generate this user's basket
  * @param type $returnType    'json' for json formatted object, else php Basket object
  * @return mixed              Basket instance or json version of Basket instance
  */
 public static function myPetBasket($userId, $returnType)
 {
     $basket = Basket::constructByUserId($userId);
     if ($returnType === 'json') {
         return json_encode($basket->__toString());
     }
     return $basket;
 }