ails)
           query (bool): Normalize the query string
           fragment (bool): Normalize the fragment
           userinfo (bool): Normalize the userinfo
           percents (bool): Encode isolated percent signs
              for any percent-encoded fields which are being
              normalized (defaults to True).

        >>> url = URL.from_text(u'Http://example.COM/a/../b/./c%2f?%61%')
        >>> print(url.normalize().to_text())
        http://example.com/b/c%2F?a%25

        .. _RFC 3986 3.2.2: https://tools.ietf.org/html/rfc3986#section-3.2.2
        .. _RFC 3986 2.3: https://tools.ietf.org/html/rfc3986#section-2.3
        .. _RFC 3986 2.1: https://tools.ietf.org/html/rfc3986#section-2.1
        .. _RFC 3986 6.2.2.3: https://tools.ietf.org/html/rfc3986#section-6.2.2.3
        .. _RFC 3986 6.2.3: https://tools.ietf.org/html/rfc3986#section-6.2.3
        .. _RFC 3986 2.4: https://tools.ietf.org/html/rfc3986#section-2.4

        r—