/** Make sure we didn't mess up our special case for [EventListener.NONE]. */
  @Test
  fun eventListenerPlusNoneAggregation() {
    val a = EventRecorder(enforceOrder = false)
    val aPlusNone = a.eventListener + EventListener.NONE

    aPlusNone.callStart(FailingCall())
    assertThat(a.takeEvent()).isInstanceOf<CallStart>()
    assertThat(a.eventSequence).isEmpty()
  }