anchor.diff:              aux     = PostAux,
               version = 0,
               timeout = new_timeout()},
  -    ContentCheck = generic_content_check(L1),
  +    ContentCheck = generic_content_check(L1, New, split_reply_step2),
       DB = get_db_for_id(Id),
       Self = comm:reply_as(self(), 9, {l_on_cseq, split_reply_step3, L2, R1, R2, Keep, ReplyTo, PostAux, '_'}),
       rbrcseq:qwrite(DB, Self, Id,
  
positive.code:    State) ->
      %log:pal("on renew ~w (~w)~n", [Old, Mode]),
      New = Old#lease{version=OldVersion+1, timeout=new_timeout()},
      ContentCheck = generic_content_check(Old),
      DB = get_db_for_id(Id),
  %% @todo New passed for debugging only:
      Self = comm:reply_as(self(), 3, {l_on_cseq, renew_reply, '_', New, Mode}),
  
negative.code: %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  
  -spec generic_content_check(lease_t(), lease_t(), atom()) ->
      fun ((any(), any(), any()) -> {boolean(), generic_failed_reason() | null}). %% content check
  generic_content_check(#lease{id=OldId,owner=OldOwner,aux = OldAux,range=OldRange,
                               epoch=OldEpoch,version=OldVersion,timeout=OldTimeout} = Old,
                       New, Writer) ->
      fun (prbr_bottom, _WriteFilter, _Next) ->
              {false, lease_does_not_exist};
          (Current, _WriteFilter, _Next) when Current =:= New ->
              ct:pal("re-write in CC:~n~w~n~w~n~w~n~w~n~w~n", [Current, _Next, Old, New, Writer]),
              {true, null};
          (#lease{id = Id0}, _, _)    when Id0 =/= OldId->
              {false, unexpected_id};
          (#lease{owner = O0}, _, _)    when O0 =/= OldOwner->
              {false, unexpected_owner};
          (#lease{aux = Aux0}, _, _)    when Aux0 =/= OldAux->
  