events.add(requestHeaders)
      notifyAll()
      return false
    }

    @Synchronized override fun onHeaders(
      streamId: Int,
      responseHeaders: List<Header>,
      last: Boolean,
    ): Boolean {
      assertThat(streamId).isEqualTo(2)
      assertThat(last).isTrue()
      events.add(responseHeaders)
      notifyAll()
      return false
    }

        return shutdown;
      }
    }

    @Override
    public void shutdown() {
      synchronized (lock) {
        shutdown = true;
        if (runningTasks == 0) {
          lock.notifyAll();
        }
      }
    }

    // See newDirectExecutorService javadoc for unusual behavior of this method.
    @Override
    public List<Runnable> shutdownNow() {
      shutdown();