},
      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 {

    taskFaker.runNextTask()
    assertThat(log).containsExactly(
      "red:starting@0",
      "blue:starting@0",
    )
    assertThat(taskFaker.executeCallCount).isEqualTo(2)

    // Advance time until the tasks complete.
    taskFaker.advanceUntil(100.µs)
    assertThat(log).containsExactly(
      "red:starting@0",
      "blue:starting@0",
      "red:finishing@100000",
      "blue:finishing@100000",