void CollectedHeap::init_obj(HeapWord* obj, size_t size) {

  {- -------------------------------------------
  (1) (変数宣言など)
      ---------------------------------------- -}

      assert(obj != NULL, "cannot initialize NULL object");
      const size_t hs = oopDesc::header_size();
      assert(size >= hs, "unexpected object size");

  {- -------------------------------------------
  (1) #TODO
      ---------------------------------------- -}

      ((oop)obj)->set_klass_gap(0);

  {- -------------------------------------------
  (1) Copy::fill_to_aligned_words() で, ヘッダー部を除いた部分を 0 クリアする 
      ---------------------------------------- -}

      Copy::fill_to_aligned_words(obj + hs, size - hs);
    }