anchor.diff:      session_setup(Worker, SessId, Cred, Self),
       [{session_id, SessId} | Config];
   
  -init_per_testcase(event_manager_test, Config) ->
  +init_per_testcase(Case, Config) when
  +    Case =:= event_stream_periodic_emission_test;
  +    Case =:= event_manager_test ->
       [Worker | _] = ?config(op_worker_nodes, Config),
       Self = self(),
       SessId = <<"session_id">>,
  
positive.code:     Handlers :: [event_stream:event_handler()]) ->
      {ok, SubId :: event_manager:subscription_id()}.
  subscribe(Worker, Producer, AdmRule, EmRule, Handlers) ->
      Sub = #write_event_subscription{
          producer = Producer,
          event_stream = ?WRITE_EVENT_STREAM#event_stream{
              metadata = 0,
              admission_rule = AdmRule,
              emission_rule = EmRule,
              handlers = Handlers
          }
      },
  
negative.code:     lists:foreach(fun(N) ->
          emit(Worker, #write_event{size = 1, counter = 1, file_size = N + 1,
              blocks = [#file_block{offset = N, size = 1}]}, SessId)
      end, lists:seq(HalfEvtsCount, EvtsCount - 1)),
  
      % Check whether event handlers have been executed.
      ?assertMatch({ok, _}, test_utils:receive_msg({handler, [#write_event{
  