         break
 
   removeParticipantFromMaps: (nickname) ->
-    return throw new Error "rtm is not set"   unless @rtm
+    return throwError "rtm is not set"   unless @rtm
 
     myWatchMapName     = "#{nickname}WatchMap"
     mySnapshotName     = "#{nickname}Snapshot"



  createChatPaneView: (channel) ->

    options = { @rtm, @isInSession }
    @getView().addSubView @chat = new IDE.ChatView options, channel



  removeParticipantFromPermissions: (nickname)->
    return throwError "permissions is not set"   unless @permissions
    # Removes the entry for the given key (if such an entry exists).
    @permissions.delete(nickname)

