def METHOD_NAME():
    # As of eventlet 0.25.1, GreenSocket.sendfile doesn't exist,
    # meaning the native implementations of socket.sendfile will be used.
    # If os.sendfile exists, it will attempt to use that, failing explicitly
    # if the socket is in non-blocking mode, which the underlying
    # socket object /is/. Even the regular _sendfile_use_send will
    # fail in that way; plus, it would use the underlying socket.send which isn't
    # properly cooperative. So we have to monkey-patch a working socket.sendfile()
    # into GreenSocket; in this method, `self.send` will be the GreenSocket's
    # send method which is properly cooperative.
    if not hasattr(GreenSocket, 'sendfile'):
        GreenSocket.sendfile = _eventlet_socket_sendfile