anchor.diff:                      {stop, normal, State#state{membership=EmptyMembership}}
               end
       end;
  +
  +%% Causal and acknowledged messages.
   handle_message({forward_message, SourceNode, MessageClock, ServerRef, {causal, Label, _, _, _, _, _} = Message},
                  #state{connections=Connections}=State) ->
       %% Try to acknowledge.
  
positive.code:     end,
  
      {reply, ok, State};
  handle_message({forward_message, ServerRef, {causal, Label, _, _, _, _, _} = Message}, State) ->
      case partisan_causality_backend:is_causal_message(Message) of
          true ->
  
negative.code:     end,
  
      {reply, ok, State};
  
  %% Best-effort messages.
  handle_message({forward_message, ServerRef, Message}, State) ->
      partisan_util:process_forward(ServerRef, Message),
      {reply, ok, State};
  
  handle_message({connect, ConnectionPid, #{name := Name} = Node}, State0) ->
      MyNode = partisan_peer_service_manager:mynode(),
  
  