# File lib/rvg/transformable.rb, line 86
        def rotate(angle, *args)
            begin
                case args.length
                    when 0
                        @transforms << [:rotate, [Float(angle)]]
                    when 2
                        cx, cy = Float(args[0]), Float(args[1])
                        @transforms << [:translate, [cx, cy]]
                        @transforms << [:rotate, [angle]]
                        @transforms << [:translate, [-cx, -cy]]
                    else
                        raise ArgumentError, "wrong number of arguments (#{args.length} for 1 or 3)"
                end
            rescue ArgumentError
                raise ArgumentError, "arguments must be convertable to float (got #{[angle, *args].collect {|a| a.class}.join(', ')})"
            end
            yield(self) if block_given?
            self
        end