Visual Studio 2015. Properties Window in Collection editor form doesn't allow to perfrom reset for the property.

Hi All

I have class in the collection with public property and 

    public int Width
    {
      get
      {
        if (widthStored)
          return width;
        else
          return DefaultWidth();
      }
      set
      {
        if ((widthStored == false) || (width != value))
        {
          widthStored = true;
          width = value;
          WidthChanged();
        }
      }
    }

    private bool ShouldSerializeWidth()
    {
      return (widthStored == true);
    }

    public void ResetWidth()
    {
      widthStored = false;
      WidthChanged();
    }

I can reset property Width in the standart Property list window

But I can't show Reset menu in the PropertyGrid of Collection editor Form.

How to make Reset menu work in Collection editor form.