static bool TryParseElement(Lexer lexer, out AuthenticationHeaderValue parsedValue, out Token t)
        {
            t = lexer.Scan();
            if (t != Token.Type.Token)
            {
                parsedValue = null;
                return(false);
            }

            parsedValue        = new AuthenticationHeaderValue();
            parsedValue.Scheme = lexer.GetStringValue(t);

            t = lexer.Scan();
            if (t == Token.Type.Token)
            {
                // TODO: Wrong with multi value parsing
                parsedValue.Parameter = lexer.GetRemainingStringValue(t.StartPosition);
                t = new Token(Token.Type.End, 0, 0);
            }

            return(true);
        }