docs: private DeleteStack getDeleteStack()
      {
          Object x = _deleteStack.get();
          DeleteStack g = null;
          if (x != null)
          {
              g = (DeleteStack) x;
              g.reset();
          }
          else
          {
              g = new DeleteStack(this);
              x = (Object) g;
              _deleteStack.set(x);
          }
          return g;
      }