anchor.diff:  
       case Message of
           undefined ->
  -            {reply, ok, State};
  +            gen_server:reply(From, ok),
  +            {noreply, State};
           _ ->
  -            handle_message(Message, State)
  +            handle_message(Message, From, State)
       end;
  -handle_call({receive_message, Message}, _From, State) ->
  -    handle_message(Message, State);
  -
  -handle_call(members_for_orchestration, _From, #state{membership=Membership}=State) ->
  -    {reply, {ok, Membership}, State};
  -
  -handle_call(members, _From, #state{membership=Membership}=State) ->
  -    Members = [P || #{name := P} <- Membership],
  -    {reply, {ok, Members}, State};
  -
  -handle_call(connections, _From, #state{connections=Connections}=State) ->
  -    {reply, {ok, Connections}, State};
  -
  -handle_call(get_local_state, _From, #state{membership_strategy_state=MembershipStrategyState}=State) ->
  -    {reply, {ok, MembershipStrategyState}, State};
  -
  -handle_call(Msg, _From, State) ->
  -    lager:warning("Unhandled call messages at module ~p: ~p", [?MODULE, Msg]),
  -    {reply, ok, State}.
  -
  -%% @private
  --spec handle_cast(term(), state_t()) -> {noreply, state_t()}.
  +
   handle_cast({forward_message, From, Name, Channel, Clock, PartitionKey, ServerRef, OriginalMessage, Options},
               #state{interposition_funs=InterpositionFuns, 
                      post_interposition_funs=PostInterpositionFuns, 
  
positive.code:             partisan_util:process_forward(ServerRef, Message)
      end,
  
      {reply, ok, State};
  
  %% Acknowledged messages.
  handle_message({forward_message, SourceNode, MessageClock, ServerRef, Message},
                 #state{connections=Connections}=State) ->
      %% Try to acknowledge.
      do_send_message(SourceNode,
  
negative.code:                     {pong, SourceNode, DestinationNode, SourceTime},
                      Connections),
  
      gen_server:reply(From, ok),
  
      {noreply, State#state{connections=Connections}};
  handle_message({pong, SourceNode, DestinationNode, SourceTime},
                 From,
                 #state{distance_metrics=DistanceMetrics0}=State) ->
      %% Compute difference.
      ArrivalTime = erlang:timestamp(),
  