How to get the routing ID of a `PEER` socket?

I am trying to get `PEER` sockets to bind and connect to each other. The [docs](https://libzmq.readthedocs.io/en/latest/zmq_socket.html) say that a message must contain a routing ID, which should be retrieved with [`zmq_connect_peer`](https://libzmq.readthedocs.io/en/latest/zmq_connect_peer.html). However, I cannot find the corresponding function in `pyzmq` and `connect` does not hold the routing ID. How can I get the routing ID for a `PEER` socket?