class Xmpp.Models.Chat extends Xmpp.Models.Model
   namespace: 'app.chat'
 
   defaults:
     who: null
     withWhom: null
 
   initialize: ->
     _.bindAll(this)
 
 class Xmpp.Collections.ChatsCollection extends Backbone.Collection
   model: Xmpp.Models.Chat
 
   initialize: ->
     _.bindAll(this)
 

     Backbone.Events.on('closeChat', (tab, chat) =>
       @removeChat(chat)
     )

 
   find: (who, withWhom) ->

     _.find(@models, (chat) ->

       chat.get('who') == who && chat.get('withWhom') == withWhom
     )
 
   removeChat: (chat) ->

     @models = _.without(@openedChats, chat)