# File lib/rvg/rvg.rb, line 162
    def background_position=(pos)
        warn "background_position= has no effect in nested RVG objects" if @nested
        bg_pos = pos.to_s.downcase
        if ! ['scaled', 'tiled', 'fit'].include?(bg_pos)
            raise ArgumentError, "background position must be `scaled', `tiled', or `fit' (#{pos} given)"
        end
        @background_position = bg_pos.to_sym
    end