docs: protected void percolateUpMaxHeap(final int index) {
          int hole = index;
          Activation element = elements[hole];
  
          while (hole > 1 && compare(element, elements[hole / 2]) > 0) {
              // save element that is being pushed down
              // as the element "bubble" is percolated up
              final int next = hole / 2;
              setElement( hole, elements[next] );
              hole = next;
          }
  
          setElement( hole, element );
      }