anchor.diff:  
   check_f_calls(F1,F2) ->
       {ok,[{{f,f1,0},F1},{{f,f2,0},F2}|_]} = cover:analyse(f,calls,function).
  +
  +cover_which_nodes(Expected) ->
  +    case cover:which_nodes() of
  +	Expected ->
  +	    ok;
  +	Other ->
  +	    {Time,ok} = timer:tc(fun Retry() ->
  +					 case cover:which_nodes() of
  +					     Expected -> ok;
  +					     _ ->
  +						 ?t:sleep(100),
  +						 Retry()
  +					 end
  +				 end),
  +	    io:format("~p ms before cover:which_nodes() returned ~p",
  +		      [Time,Expected]),
  +	    Expected = Other
  +    end.
  
positive.code:     %% Stop cover on the node, then terminate the node
      cover:stop(N1),
      rpc:call(N1,erlang,halt,[]),
      [] = cover:which_nodes(),
  
      check_f_calls(1,0),
  
  
negative.code:     {ok,N1} = ?t:start_node(NodeName,peer,
  			    [{args," -pa " ++ DataDir},{start_cover,false}]),
      timer:sleep(300),
      cover_which_nodes([]),
      Beam = rpc:call(N1,code,which,[f]),
      false = (Beam==cover_compiled),
  
  