K&B simply means that if you are searching an array which you have previously sorted with a Comparator, it is a must when you call
binary search method then you pass the comparator even else the results will be un-predictable.
The version which is called in that line is without the comparator being passed.
Additionally, please put the question separately from the code tags as it is hard for the reader to understand your question. It will simply
add delay to your reply.