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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 main(port=8222):
 """ 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()