code: public static int binarySearchGreater(int[] index, int key, int begin,
              int end) {
          return binarySearchInterval(index, key, begin, end, true);
      }
docs: Searches for a key in a sorted array, and returns an index to an element
  which is greater than or equal key.
  
  @param index
  Sorted array of integers
  @param key
  Search for something equal or greater
  @param begin
  Start posisiton in the index
  @param end
  One past the end position in the index
  @return end if nothing greater or equal was found, else an index
  satisfying the search criteria