private final Queue<E> delegate = new LinkedList<>();
    private final Object mutex = new Object[0]; // something Serializable

    @Override
    public boolean offer(E o) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.offer(o);
    }

    @Override
    public @Nullable E poll() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.poll();
    }

    @Override

    <glob pattern="*.clj"/>
    <sub-class-of type="text/plain"/>
  </mime-type>

  <mime-type type="text/x-coffeescript">
    <_comment>CoffeeScript source code</_comment>
    <glob pattern="*.coffee"/>
    <sub-class-of type="text/plain"/>
  </mime-type>

  <mime-type type="text/x-csrc">
    <alias type="text/x-c"/>
    <_comment>C source code</_comment>
    <magic priority="30">

 * methods of the delegate. For example, overriding {@link #add} alone <b>will not</b> change the
 * behavior of {@link #offer} which can lead to unexpected behavior. In this case, you should
 * override {@code offer} as well, either providing your own implementation, or delegating to the
 * provided {@code standardOffer} method.
 *

   */
  @CanIgnoreReturnValue // pushed down from class to method
  @Override
  public boolean add(E e) {
    return offer(e);
  }

  /**
   * Inserts the specified element into this priority queue.
   *
   * @param e the element to add
   * @return {@code true} (as specified by {@link Queue#offer})
   * @throws ClassCastException if the specified element cannot be compared with elements currently

    private final Deque<E> delegate = new LinkedList<>();
    private final Object mutex = new Object[0]; // something Serializable

    @Override
    public boolean offer(E o) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.offer(o);
    }

    @Override
    public @Nullable E poll() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.poll();
    }

    @Override

    return delegate().drainTo(c);
  }

  @CanIgnoreReturnValue // TODO(kak): consider removing this
  @Override
  public boolean offer(E e, long timeout, TimeUnit unit) throws InterruptedException {
    return delegate().offer(e, timeout, unit);
  }

  @CanIgnoreReturnValue // TODO(kak): consider removing this
  @Override

    return delegate().drainTo(c);
  }

  @CanIgnoreReturnValue // TODO(kak): consider removing this
  @Override
  public boolean offer(E e, long timeout, TimeUnit unit) throws InterruptedException {
    return delegate().offer(e, timeout, unit);
  }

  @CanIgnoreReturnValue // TODO(kak): consider removing this
  @Override

 * to the methods of the delegate. For example, overriding {@link #add} alone <b>will not</b> change
 * the behaviour of {@link #offer} which can lead to unexpected behaviour. In this case, you should
 * override {@code offer} as well, either providing your own implementation, or delegating to the
 * provided {@code standardOffer} method.
 *

 * methods of the delegate. For example, overriding {@link #add} alone <b>will not</b> change the
 * behavior of {@link #offer} which can lead to unexpected behavior. In this case, you should
 * override {@code offer} as well.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code

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

    if (enforceOrder) {
      checkForStartEvent(e)
    }

    eventsForMatching.offer(e)
    eventSequence.offer(e)
  }

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