anchor.diff:                      lager:info("~p: Message after send interposition is: ~p", [node(), Message]),
   
                       %% Acknowledgements.
  -                    RescheduleableMessage = {forward_message, From, Name, Channel, MessageClock, PartitionKey, ServerRef, OriginalMessage, Options},
  -                    partisan_acknowledgement_backend:store(MessageClock, RescheduleableMessage),
  +                    case proplists:get_value(retransmission, Options, false) of 
  +                        false ->
  +                            RescheduleableMessage = {forward_message, From, Name, Channel, MessageClock, PartitionKey, ServerRef, OriginalMessage, Options},
  +                            partisan_acknowledgement_backend:store(MessageClock, RescheduleableMessage);
  +                        true ->
  +                            ok
  +                    end,
   
                       %% Send message along.
                       do_send_message(Name,
  
positive.code: 
              %% Gossip the new membership.
              lists:foreach(fun({Peer, Message}) ->
                  schedule_message_delivery(Peer, Message, ?MEMBERSHIP_PROTOCOL_CHANNEL, ?DEFAULT_PARTITION_KEY, PreInterpositionFuns)
              end, OutgoingMessages),
  
              %% Announce to the peer service.
  
negative.code: handle_call({receive_message, Peer, OriginalMessage}, 
              From, 
              #state{pre_interposition_funs=PreInterpositionFuns}=State) ->
      %% lager:info("number of receive_message pre_interposition_funs ~p", [length(dict:to_list(PreInterpositionFuns))]),
  
      %% Run all interposition functions.
      DeliveryFun = fun() ->
  