 
     if link and data[link]
       if @subscriptions[subsName] and not _.isEmpty @subscriptions[subsName]
-        oldIds = _.map @subscriptions[subsName], (doc) ->
-          return doc._id
-
-        newIds = _.map data[link], (doc) ->
-          return doc._id
+        oldIds = (doc._id for doc in @subscriptions[subsName])
+        newIds = (doc._id for doc in data[link])
 
         diff = _.difference oldIds, newIds
         if diff and not _.isEmpty diff

    check methodName, String
    check opts, Match.Optional Match.OneOf Object, null

    for param in arguments
      callback = param if _.isFunction param

    Meteor.call methodName, opts, name, link, (error, uid) ->
      if error
        throw new Meteor.Error '500', '[Meteor.neo4j.call] Method: ["#{methodName}"] returns error!', error
      else
        Meteor.neo4j.uids.set _.union(Meteor.neo4j.uids.get(), [ uid ])
        return Meteor.neo4j.cache.get(uid, callback)
  ) else undefined

###

        else
          _id = doc._id

        doc._id = _.clone _id

        @subscriptions[subsName].push _.clone doc

