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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def parse_ipv6_hostname(cls, hostname):
        '''Parse and normalize a IPv6 address.'''
        if not hostname.startswith('[') or not hostname.endswith(']'):
            raise ValueError('Invalid IPv6 address: {}'
                             .format(ascii(hostname)))

        hostname = ipaddress.IPv6Address(hostname[1:-1]).compressed

        return hostname