code: public int binarySearch (T key, Comparator<? super T> comp)
      {
          return ArrayUtil.binarySearch(_elements, 0, _size, key, comp);
      }
docs: Performs a binary search, attempting to locate the specified
  object. The array must be in the sort order defined by the supplied
  {@link Comparator} for this to operate correctly.
  
  @return the index of the object in question or
  <code>(-(<i>insertion point</i>) - 1)</code> (always a negative
  value) if the object was not found in the list.