def keywords(args)
      assert_type args, :ArgList, :args
      map(Sass::Util.map_keys(args.keywords.as_stored) {|k| Sass::Script::Value::String.new(k)})
    end
def keywords(args)
      assert_type args, :ArgList, :args
      map(Sass::Util.map_keys(args.keywords.as_stored) {|k| Sass::Script::Value::String.new(k)})
    end
Returns the map of named arguments passed to a function or mixin that
 takes a variable argument list. The argument names are strings, and they
 do not contain the leading `$`.

 @example
   @mixin foo($args...) {
     @debug keywords($args); //=> (arg1: val, arg2: val)
   }

   @include foo($arg1: val, $arg2: val);
 @overload keywords($args)
   @param $args [Sass::Script::Value::ArgList]
 @return [Sass::Script::Value::Map]
 @raise [ArgumentError] if `$args` isn't a variable argument list