       avatar        : String
       group         : ObjectId
       invitees      :
-        type        : [String]
-        default     : -> []
-      participants  :
         type        : [String]
         default     : -> []
       tags          : [ObjectRef]

    {delegate} = client.connection
    {nickname} = delegate.profile

    delegateCanInvite = nickname? and
                        nickname in [@createdBy].concat @participants

    return callback new KodingError "Access denied!" unless delegateCanInvite


    {delegate} = client.connection
    {nickname} = delegate.profile

    initialInvitees.push nickname

    initialInvitees = uniq initialInvitees

    conversation = new this {
      publicName  : createId()
      createdBy   : nickname
    }

    @one { invitees: initialInvitees }, (err, conversation)->
      return callback err  if err
