@Override
    public void pushWhenNoDuplicate(Request request, Task task) {
        logger.trace("Remaining capacity: {}", this.queue.remainingCapacity());

        try {
            queue.put(request);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
    }
Creates a {@code QueueScheduler} with the given (fixed) capacity.

@param capacity the capacity of this queue,
see {@link LinkedBlockingQueue#LinkedBlockingQueue(int)}
@since 0.8.0
webmagic-core/src/main/java/us/codecraft/webmagic/scheduler/QueueScheduler.java