Request executor after kill executor, the number of executors is not as expected

test("kill executors first and then request") {
    sc = new SparkContext(appConf
      .set(config.EXECUTOR_CORES, 2)
      .set(config.CORES_MAX, 8))
    val appId = sc.applicationId
    eventually(timeout(10.seconds), interval(10.millis)) {
      val apps = getApplications()
      assert(apps.size === 1)
      assert(apps.head.id === appId)
      assert(apps.head.executors.size === 4) // 8 cores total
      assert(apps.head.getExecutorLimit === Int.MaxValue)
    }
    // sync executors between the Master and the driver, needed because
    // the driver refuses to kill executors it does not know about
    syncExecutors(sc)
    val executors = getExecutorIds(sc)
    assert(executors.size === 4)
    // kill 2 executors
    assert(sc.killExecutors(executors.take(3)))
    val apps = getApplications()
    assert(apps.head.executors.size === 1)
    // add 2 executors
    assert(sc.requestExecutors(3))
    assert(apps.head.executors.size === 4)
  }