anchor.diff:          code = 0,
           to_tags = [],
           cancel = undefined,
  -        iter = 1,
  -        meta = []
  +        iter = 1
       },
       Msg = {MsgId, Id, DialogId},
       {UAC, Call#call{trans=[UAC|Trans], msgs=[Msg|Msgs], next=Id+1}}.
  
positive.code:     {CSeq, Call1} = nksip_call_uac_dialog:new_local_seq(Req, Call),
      Req1 = Req#sipmsg{vias=Vias, cseq=CSeq},
      % Contact would be already generated
      Opts1 = nksip_lib:delete(Opts, make_contact),
      {NewUAC, Call2} = new_uac(Req1, Opts1, From, Call1),
      NewUAC1 = NewUAC#trans{iter=Iter+1},
      send(NewUAC1, update(NewUAC1, Call2)).
  
negative.code:         id = Id,
          status = Status,
          opts = Opts,
          method = Method,
          iter = Iter,
          from = From
      } = UAC,
  