anchor.diff:  
   %% @private
   remove_node_monitor(Node, Pid, State) ->
  -    case maps:find(Node, State#state.pids_by_node) of
  -        {ok, Existing} ->
  -            State#state{pids_by_node = lists:delete(Pid, Existing)};
  +    Map0 = State#state.pids_by_node,
  +    case maps:find(Node, Map0) of
  +        {ok, Pids} when is_list(Pids) ->
  +            Map1 = maps:put(Node, lists:delete(Pid, Pids), Map0),
  +            State#state{pids_by_node = Map1};
           error ->
               State
       end.
  
positive.code:     end;
  
  handle_call({demonitor_node, Node}, {Pid, _}, State0) ->
      State = remove_node_monitor(Node, Pid, State0),
      {reply, true, State};
  
  handle_call(_Msg, _From, State) ->
  
negative.code:     Ref.
  
  
  decode_pid(
      {partisan_remote_reference, _, {partisan_process_reference, PidAsList}}) ->
      erlang:list_to_pid(PidAsList);
  
  decode_pid(Pid) when is_pid(Pid) ->
      Pid.
  