# File lib/sass/script/functions.rb, line 574
      def assert_integer(number, name = nil)
        assert_type number, :Number, name
        return if number.int?
        if name
          raise ArgumentError.new("Expected $#{name} to be an integer but got #{number}")
        else
          raise ArgumentError.new("Expected #{number} to be an integer")
        end
      end