'Return the Apache addresses needed for TLS-SNI-01.'

def _get_addrs(self, achall):

    addrs = set()
    default_addr = obj.Addr(('*', str(self.configurator.config.tls_sni_01_port)))
    try:
        vhost = self.configurator.choose_vhost(achall.domain, temp=True)
    except (PluginError, MissingCommandlineFlag):
        logger.warning('Falling    back    to    default    vhost    %s...', default_addr)
        addrs.add(default_addr)
        return addrs
    for addr in vhost.addrs:
        if ('_default_' == addr.get_addr()):
            addrs.add(default_addr)
        else:
            addrs.add(addr.get_sni_addr(self.configurator.config.tls_sni_01_port))
    return addrs
