def background_image=(bg_image)
      warn 'background_image= has no effect in nested RVG objects' if @nested
      raise ArgumentError, "background image must be an Image (got #{bg_image.class})" if bg_image && !bg_image.is_a?(Magick::Image)

      @background_image = bg_image
    end
def background_image=(bg_image)
      warn 'background_image= has no effect in nested RVG objects' if @nested
      raise ArgumentError, "background image must be an Image (got #{bg_image.class})" if bg_image && !bg_image.is_a?(Magick::Image)

      @background_image = bg_image
    end
Sets an image to use as the canvas background. See background_position= for layout options.