anchor.diff:      end;
   node_postcondition(_NodeState, {call, ?MODULE, set_fault, [_Node, _Value]}, ok) ->
       true;
  +node_postcondition(_NodeState, {call, ?MODULE, wait, [_Node]}, _Result) ->
  +    true;
   node_postcondition(_NodeState, {call, ?MODULE, sleep, []}, _Result) ->
       true;
   node_postcondition(_NodeState, {call, ?MODULE, next_id, [_Node]}, {badrpc,timeout}) ->
  
positive.code:     node_debug("postcondition received ~p from max_id", [Results]),
  
      CorrectNodes = lists:filter(fun({Node, Result}) -> 
          case Counter =:= Result of
              true ->
                  true;
              false ->
  
negative.code: 
  %% Precondition.
  node_precondition(_NodeState, {call, ?MODULE, sleep, []}) ->
      true;
  node_precondition(_NodeState, {call, ?MODULE, wait, [_Node]}) ->
      true;
  node_precondition(_NodeState, {call, ?MODULE, set_fault, [_Node, _Value]}) ->
      true;
  