for (lock in forbiddenLocks) {
      assertThat(Thread.holdsLock(lock), "Called with lock $lock")
        .isFalse()
    }

    if (enforceOrder) {
      checkForStartEvent(e)
    }

    eventSequence.offer(e)
  }

  private fun checkForStartEvent(e: ConnectionEvent) {
    if (eventSequence.isEmpty()) {
      assertThat(e).isInstanceOf(ConnectionEvent.ConnectStart::class.java)
    } else {

    for (lock in forbiddenLocks) {
      assertThat(Thread.holdsLock(lock), lock.toString()).isFalse()
    }

    if (enforceOrder) {
      checkForStartEvent(e)
    }

    eventSequence.offer(e)
  }

  private fun checkForStartEvent(e: CallEvent) {
    if (eventSequence.isEmpty()) {
      assertThat(e).matchesPredicate { it is CallStart || it is Canceled }
    } else {