How to use the asyncssh.create_server function in asyncssh

async def start_ssh_server(q):
    global server_port,server_q
    listener = await asyncssh.create_server(MySSHServer,'127.0.0.1',server_port,server_host_keys=['tests'+os.path.sep+'ssh_host_key'],process_factory=handle_client,sftp_factory=True,allow_scp=True)
    for item in listener.sockets:
        server_q.put(item.getsockname()[1])
        break

:return:
    '''
    await asyncssh.listen(host='',
                          port=sftp_port,
                          authorized_client_keys=authorized_client_keys,
                          server_host_keys=[server_host_keys],
                          sftp_factory=sftp_factory,
                          **kwargs)

    # 'reuse_address' probably also has to be `True` in this case
    if kwargs.get('reuse_port') and not ssh_port:
        ssh_port = sftp_port

    # Don't create the ssh server unless there is a port available for it
    if ssh_port:
        await asyncssh.create_server(
            host='',
            server_factory=server_factory,
            port=ssh_port,
            authorized_client_keys=authorized_client_keys,
            server_host_keys=[server_host_keys],
        )

async def test_no_server_host_keys(self):
        """Test starting a server with no host keys"""

        with self.assertRaises(ValueError):
            await asyncssh.create_server(Server, server_host_keys=[],
                                         gss_host=None)

Example that starts the REPL through an SSH server.
    """
    loop = asyncio.get_event_loop()

    # Namespace exposed in the REPL.
    environ = {'hello': 'world'}

    # Start SSH server.
    def create_server():
        return MySSHServer(lambda: environ)

    print('Listening on :%i' % port)
    print('To connect, do "ssh localhost -p %i"' % port)

    loop.run_until_complete(
        asyncssh.create_server(create_server, '', port,
                               server_host_keys=['/etc/ssh/ssh_host_dsa_key']))

    # Run eventloop.
    loop.run_forever()

def main(port=8222):
    # Set up logging.
    logging.basicConfig()
    logging.getLogger().setLevel(logging.DEBUG)

    loop = asyncio.get_event_loop()
    loop.run_until_complete(
        asyncssh.create_server(
            lambda: PromptToolkitSSHServer(interact),
            "",
            port,
            server_host_keys=["/etc/ssh/ssh_host_ecdsa_key"],
        )
    )
    loop.run_forever()

async def interact():
        nonlocal uis, permenantly_closed
        if permenantly_closed:
            return
        ui = FullNodeUI(store, blockchain, server, port, ui_close_cb)
        assert ui.app
        uis.append(ui)
        try:
            await ui.app.run_async()
        except ConnectionError:
            log.info("Connection error in ssh UI, exiting.")
            ui.close()
            raise

    ssh_server = await asyncssh.create_server(
        lambda: PromptToolkitSSHServer(interact),
        "",
        ssh_port,
        server_host_keys=[ssh_key_filename],
        reuse_address=True,
    )

    return await_all_closed, ui_close_cb

async def start_server():
    await asyncssh.create_server(MySSHServer, '', 8022,
                                 server_host_keys=['ssh_host_key'],
                                 authorized_client_keys='ssh_user_ca')