// there's a way around creating the separate sortedKeys array, and if we're allocating
          // one array of size n, we might as well allocate two -- to say nothing of the allocation
          // done in Arrays.sort.
          for (int i = 0; i < size; i++) {
            // We're careful to put only K instances in.
            if (i > 0 && comparator.compare((K) sortedKeys[i - 1], (K) sortedKeys[i]) == 0) {