int initialCapacity, @Nullable Comparator<? super E> comparator) {
    q = new PriorityQueue<E>(initialCapacity, comparator);
  }

  /**
   * Creates a {@code MonitorBasedPriorityBlockingQueue} containing the elements in the specified
   * collection. If the specified collection is a {@link SortedSet} or a {@link PriorityQueue}, this
   * priority queue will be ordered according to the same ordering. Otherwise, this priority queue