code: function(objects, options) {
            var idSet = new Set(objects.map(function(object) {
              return object._id
            }))
            if (idSet.length < objects.length) {
              throw new this.getService().errors.BadRequest('Duplicate IDs')
            }
            this.cache = objects
            return objects
          }
docs: post-findObject-memCacheCounterAdvanced pre-save-memCacheCounterAdvanced