Helper method for creating a connection to an ``address``.

async def create_connection(self, address=None, protocol_factory=None,
                                **kwargs):
        """Helper method for creating a connection to an ``address``.
        """
        loop = self._loop
        protocol_factory = protocol_factory or self.create_protocol
        if isinstance(address, tuple):
            kwargs['host'] = address[0]
            kwargs['port'] = address[1]
        _, protocol = await loop.create_connection(protocol_factory, **kwargs)
        event = protocol.event('connection_made')
        if not event.fired():
            await event.waiter()
        return protocol