def inflate_by_size(sz)
      width  = sz.width
      height = sz.height
      validate(width, height)

      @width  += width
      @height += height

      self
    end
def inflate_by_size(sz)
      width  = sz.width
      height = sz.height
      validate(width, height)

      @width  += width
      @height += height

      self
    end
Change the dimensions using the dimensions of another Size.