anchor.diff:                                      Channel,
                                       PartitionKey,
                                       WrappedMessage,
  -                                    Connections);
  +                                    Connections,
  +                                    ForwardOptions,
  +                                    PreInterpositionFuns);
                   true ->
                       %% Tracing.
                       WrappedOriginalMessage = {forward_message, mynode(), MessageClock, ServerRef, OriginalMessage},
  
positive.code: 
      %% Transmit outgoing messages.
      lists:foreach(fun({Peer, Message}) ->
                  do_send_message(Peer,
                                  ?MEMBERSHIP_PROTOCOL_CHANNEL,
                                  ?DEFAULT_PARTITION_KEY,
                                  Message,
                                  Connections)
          end, OutgoingMessages),
  
      case partisan_config:get(connect_disterl) of 
          true ->
  
negative.code: 
      %% Are we using causality?
      CausalLabel = proplists:get_value(causal_label, Options, undefined),
  
      %% Get forwarding options.
      ForwardOptions = partisan_config:get(forward_options, []),
  
      %% Use local information for message unless it's a causal message.
      {MessageClock, FullMessage} = case CausalLabel of
  