code: public static void makeHeap(Quicksortable q, int size) {
          for (int i = (size-1)/2; i >= 0; i--) {
              heapifyDown(q, i, size);
          }
      }
docs: Makes a heap with the elements [0, size) of q
  
  @param q The quicksortable to transform into a heap.
  @param size The size of the quicksortable.