},
      logger = logger,
    )

  /** Runs all tasks that are ready. Used by the test thread only. */
  fun runTasks() {
    advanceUntil(nanoTime)
  }

  /** Advance the simulated clock, then runs tasks that are ready. Used by the test thread only. */
  fun advanceUntil(newTime: Long) {
    taskRunner.assertThreadDoesntHoldLock()

    taskRunner.lock.withLock {

    )
  }

  /**
   * The runner doesn't hold references to its queues! Otherwise we'd need a mechanism to clean them
   * up when they're no longer needed and that's annoying. Instead the task runner only tracks which
   * queues have work scheduled.
   */
  @Test fun activeQueuesContainsOnlyQueuesWithScheduledTasks() {
    redQueue.execute("task one", 100.µs) {
      // Do nothing.
    }