anchor.diff:  
   INFO: This template can easily be customized to consider more user events such as *rate* and *like*.
   
  -The *view* events are used as Training Data to train the model. The algorithm has a paramter *unseenOnly* so the engine would recommend unseen items only when it's set to true. You can specify a list of events which are considered as *seen* events with the algoritm paramter *seenEvents*. The default value is *view* and *buy* events, which means that the engine recommends unviewed and unbought items only. You can also define your own events which are considered as *seen*.
  +The *view* events are used as Training Data to train the model. The algorithm has a parameter *unseenOnly*; when this parameter is set to true, the engine would recommend unseen items only. You can specify a list of events which are considered as *seen* events with the algorithm parameter *seenEvents*. The default values are *view* and *buy* events, which means that the engine by default recommends un-viewed and un-bought items only. You can also define your own events which are considered as *seen*.
   
   The constraint *unavailableItems* set events are used to exclude a list of unaviable items (such as out of stock) for all users in real time.
   
  
positive.code: }'
  ```
  
  Try to get recommendation for user *u1* again, you will see the unavaiable items (e.g. i4, i14, i11). won't be recommended anymore:
  
  ```
  curl -H "Content-Type: application/json" \
  
negative.code: ```
  
  
  