Negotiates a stream connection through a SOCKS5 server.

def _negotiate_SOCKS5(self, *dest_addr):
        """
        Negotiates a stream connection through a SOCKS5 server.
        """
        CONNECT = b"\x01"
        self.proxy_peername, self.proxy_sockname = self._SOCKS5_request(self,
            CONNECT, dest_addr)