Javadoc
Starts the built-in 0MQ proxy in the current application thread. The proxy connects a frontend socket to a
backend socket. Conceptually, data flows from frontend to backend. Depending on the socket types, replies may
flow in the opposite direction. The direction is conceptual only; the proxy is fully symmetric and there is no
technical difference between frontend and backend.
Before calling ZMQ.proxy() you must set any socket options, and connect or bind both frontend and backend
sockets. The two conventional proxy models are:
ZMQ.proxy() runs in the current thread and returns only if/when the current context is closed.