Review

class ScorerDocQueue {
  private final void upHeap() {
    int i = size;
    HeapedScorerDoc node = heap[i];		  // save bottom node
    int j = i >>> 1;
    while ((j > 0) && (node.doc < heap[j].doc)) {
      heap[i] = heap[j];			  // shift parents down
      i = j;
      j = j >>> 1;
    }
    heap[i] = node;				  // install saved node
    topHSD = heap[1];
  }

}