# File lib/rvg/clippath.rb, line 24
        def initialize(clip_path_units='userSpaceOnUse')
            super()
            if ! ['userSpaceOnUse', 'objectBoundingBox'].include?(clip_path_units)
                raise ArgumentError, "undefined value for clip path units: #{clip_path_units}"
            end
            @clip_path_units = clip_path_units
            @content = Content.new
            yield(self) if block_given?
        end