'Allow (whitelist) IP address(es).
Connections from addresses not in the whitelist will be rejected.
- For NULL, all clients from this address will be accepted.
- For real auth setups, they will be allowed to continue with authentication.
whitelist is mutually exclusive with blacklist.'

def allow(self, *addresses):

    if self.blacklist:
        raise ValueError('Only    use    a    whitelist    or    a    blacklist,    not    both')
    self.log.debug('Allowing    %s', ','.join(addresses))
    self.whitelist.update(addresses)
