code: long swapRandomTagInBucket(long curIndex, long tag) {
  		int randomBucketPosition = ThreadLocalRandom.current().nextInt(CuckooFilter.BUCKET_SIZE);
  		return readTagAndSet(curIndex, randomBucketPosition, tag);
  	}
docs: Replaces a tag in a random position in the given bucket and returns the
  tag that was replaced.
  
  @param curIndex
  bucket index
  @param tag
  tag
  @return the replaced tag