code: public void enqueuePathQuery(final byte[] pathQuery) {
  		synchronized (this) {
  			if (nextFetch == Long.MAX_VALUE) return;
  			final boolean wasEmpty = pathQueries.isEmpty();
  			pathQueries.enqueue(pathQuery);
  			if (wasEmpty) putInEntryIfNotAcquired();
  		}
  		frontier.pathQueriesInQueues.incrementAndGet();
  		frontier.weightOfpathQueriesInQueues.addAndGet(BURL.memoryUsageOf(pathQuery));
  	}
docs: Enqueues a path+query in byte-array representation, possibly putting this visit state in its
  entry.
  
  <p>Note that if you enqueue more than once the same URL to a visit state using
  this method, it will be fetched twice. Thus, this method should be called only
  by the {@linkplain NewFlowReceiver receiver of new flows from the sieve}.
  
  <p>Note that the scheme+authority of <code>url</code> must be {@link #schemeAuthority}.
  
  @param pathQuery a path+query in byte-array representation.