} catch (Exception e) {
          future.completeExceptionally(e);
        }
      }

      @Override
      public void onEvent(@NotNull EventSource eventSource, @Nullable String id, @Nullable String type, @NotNull String data) {
        try {
          assertEquals("hello", data);
          future.complete(null);
        } catch (Exception e) {
          future.completeExceptionally(e);
        }
      }

      @Override