anchor.diff:      % given
       test_utils:mock_expect(Workers, router, route_message, fun
           (#client_message{message_id = Id = #message_id{issuer = Issuer,
  -            recipient = undefined}}, _, _) ->
  +            recipient = undefined}}, _, _, _) ->
               Issuer = oneprovider:get_id(),
               Self ! {router_message_called, Id},
               ok
  
positive.code:     test_utils:mock_expect(Workers, router, route_message, fun
          (#client_message{message_body = #events{events = [#event{
              type = #file_read_event{counter = Counter}
          }]}}, _, _) ->
              Self ! Counter,
              ok
      end),
  
negative.code:     initializer:remove_pending_messages(),
      Self = self(),
      test_utils:mock_expect(Workers, router, route_message, fun
          (#client_message{message_body = #ping{}}, _, _, _) ->
              Self ! router_message_called,
              ok;
          (_, _, _, _) ->
              ok
      end),
  
  