anchor.diff:               comm:erl_local_pid(),
                ?RT:key(),
                fun ((any()) -> any()), %% read filter
  -             fun ((any(), any(), any()) -> any()), %% content check
  +             fun ((any(), any(), any()) -> {boolean(), any()}), %% content check
                fun ((any(), any(), any()) -> any()), %% write filter
   %%              %% select what you need to read for the operation
   %%              fun ((CustomData) -> ReadInfo),
  
positive.code: -spec qwrite_fast(pid_groups:pidname(),
                    comm:erl_local_pid(),
                    ?RT:key(),
                    fun ((any(), any(), any()) -> any()), %% CC (Content Check)
                    client_value(), prbr:r_with_id(),
                    client_value() | prbr_bottom) -> ok.
  qwrite_fast(CSeqPidName, Client, Key, CC, Value, Round, OldVal) ->
  
negative.code: -spec qwrite(pid_groups:pidname(),
               comm:erl_local_pid(),
               ?RT:key(),
               fun ((any(), any(), any()) -> {boolean(), any()}), %% CC (Content Check)
               client_value()) -> ok.
  qwrite(CSeqPidName, Client, Key, CC, Value) ->
      RF = fun prbr:noop_read_filter/1,
  