# File lib/sass/script/functions.rb, line 527
      def assert_type(value, type, name = nil)
        klass = Sass::Script::Value.const_get(type)
        return if value.is_a?(klass)
        return if value.is_a?(Sass::Script::Value::List) && type == :Map && value.value.empty?
        err = "#{value.inspect} is not a #{TYPE_NAMES[type] || type.to_s.downcase}"
        err = "$#{name.to_s.gsub('_', '-')}: " + err if name
        raise ArgumentError.new(err)
      end