anchor.diff:  
   worker_unregister_on_node(FromName, ToName) when FromName > ToName -> ok;
   worker_unregister_on_node(Name, ToName) ->
  -    ok = syn:unregister(Name),
  +    ok = syn:unregister(?TEST_SCOPE, Name),
       worker_unregister_on_node(Name + 1, ToName).
   
   join_on_node(CollectorPid, WorkersPerNode, Pids) ->
  
positive.code: 
  worker_leave_on_node([]) -> ok;
  worker_leave_on_node([Pid | PidsTail]) ->
      ok = syn:leave(?TEST_GROUP_NAME, Pid),
      worker_leave_on_node(PidsTail).
  
  wait_done_on_node(CollectorPid, Time, 0) ->
  
negative.code:             io:format("      --> MIN: ~p secs.~n", [lists:min(JoinRemoteNodesTimes)]),
              io:format("      --> MAX: ~p secs.~n", [lists:max(JoinRemoteNodesTimes)]),
  
              {JoinPropagationTimeMs, _} = timer:tc(?MODULE, wait_pg_propagation, [ProcessCount]),
              JoinPropagationTime = JoinPropagationTimeMs / 1000000,
              io:format("----> Eventual additional time to propagate all to master: ~p secs.~n", [JoinPropagationTime]),
  
  