code: function(store, snapshot, url, relationship) {
          var belongsTo = snapshot.belongsTo(relationship.key);
          var belongsToLoaded = belongsTo && !belongsTo.record.get('_internalModel.currentState.isEmpty');
  
          if(belongsToLoaded) {
            return;
          }
  
          return this._super(store, snapshot, url, relationship);
        }
docs: Suppress additional API calls if the relationship was already loaded via an `included` section