def __init__(self, reactor, fileno, addressFamily):
        """
        @param reactor: An L{IReactorSocket} provider.

        @param fileno: An integer file descriptor corresponding to a listening
            I{SOCK_STREAM} socket.

        @param addressFamily: The address family of the socket given by
            C{fileno}.
        """
        self.reactor = reactor
        self.fileno = fileno
        self.addressFamily = addressFamily
        self._used = False

        @param reactor: An L{IReactorSocket} provider.

        @param fileno: An integer file descriptor corresponding to a listening
            I{SOCK_STREAM} socket.

        @param addressFamily: The address family of the socket given by
            C{fileno}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/endpoints.py