How to use the sshuttle.helpers.b function in sshuttle

def udp_req(channel, cmd, data):
        debug2('Incoming UDP request channel=%d, cmd=%d\n' % (channel, cmd))
        if cmd == ssnet.CMD_UDP_DATA:
            (dstip, dstport, data) = data.split(b(','), 2)
            dstport = int(dstport)
            debug2('is incoming UDP data. %r %d.\n' % (dstip, dstport))
            h = udphandlers[channel]
            h.send((dstip, dstport), data)
        elif cmd == ssnet.CMD_UDP_CLOSE:
            debug2('is incoming UDP close\n')
            h = udphandlers[channel]
            h.ok = False
            del mux.channels[channel]

def hostwatch_ready(sock):
        assert(hw.pid)
        content = hw.sock.recv(4096)
        if content:
            lines = (hw.leftover + content).split(b('\n'))
            if lines[-1]:
                # no terminating newline: entry isn't complete yet!
                hw.leftover = lines.pop()
                lines.append(b(''))
            else:
                hw.leftover = b('')
            mux.send(0, ssnet.CMD_HOST_LIST, b('\n').join(lines))
        else:
            raise Fatal('hostwatch process died')

def hostwatch_ready(sock):
        assert(hw.pid)
        content = hw.sock.recv(4096)
        if content:
            lines = (hw.leftover + content).split(b('\n'))
            if lines[-1]:
                # no terminating newline: entry isn't complete yet!
                hw.leftover = lines.pop()
                lines.append(b(''))
            else:
                hw.leftover = b('')
            mux.send(0, ssnet.CMD_HOST_LIST, b('\n').join(lines))
        else:
            raise Fatal('hostwatch process died')

def hostwatch_ready(sock):
        assert(hw.pid)
        content = hw.sock.recv(4096)
        if content:
            lines = (hw.leftover + content).split(b('\n'))
            if lines[-1]:
                # no terminating newline: entry isn't complete yet!
                hw.leftover = lines.pop()
                lines.append(b(''))
            else:
                hw.leftover = b('')
            mux.send(0, ssnet.CMD_HOST_LIST, b('\n').join(lines))
        else:
            raise Fatal('hostwatch process died')

def callback(self, sock):
        try:
            data, peer = sock.recvfrom(4096)
        except socket.error:
            _, e = sys.exc_info()[:2]
            log('UDP recv from %r port %d: %s\n' % (peer[0], peer[1], e))
            return
        debug2('UDP response: %d bytes\n' % len(data))
        hdr = b("%s,%r," % (peer[0], peer[1]))
        self.mux.send(self.chan, ssnet.CMD_UDP_DATA, hdr + data)

def send(self, channel, cmd, data):
        assert isinstance(data, binary_type)
        assert len(data) <= 65535
        p = struct.pack('!ccHHH', b('S'), b('S'), channel, cmd, len(data)) \
            + data
        self.outbuf.append(p)
        debug2(' > channel=%d cmd=%s len=%d (fullness=%d)\n'
               % (channel, cmd_to_name.get(cmd, hex(cmd)),
                  len(data), self.fullness))
        self.fullness += len(data)

def __init__(self, rsock, wsock):
        Handler.__init__(self, [rsock, wsock])
        self.rsock = rsock
        self.wsock = wsock
        self.new_channel = self.got_dns_req = self.got_routes = None
        self.got_udp_open = self.got_udp_data = self.got_udp_close = None
        self.got_host_req = self.got_host_list = None
        self.channels = {}
        self.chani = 0
        self.want = 0
        self.inbuf = b('')
        self.outbuf = []
        self.fullness = 0
        self.too_full = False
        self.send(0, CMD_PING, b('chicken'))

def handle(self):
        self.fill()
        # log('inbuf is: (%d,%d) %r\n'
        #     % (self.want, len(self.inbuf), self.inbuf))
        while 1:
            if len(self.inbuf) >= (self.want or HDR_LEN):
                (s1, s2, channel, cmd, datalen) = \
                    struct.unpack('!ccHHH', self.inbuf[:HDR_LEN])
                assert(s1 == b('S'))
                assert(s2 == b('S'))
                self.want = datalen + HDR_LEN
            if self.want and len(self.inbuf) >= self.want:
                data = self.inbuf[HDR_LEN:self.want]
                self.inbuf = self.inbuf[self.want:]
                self.want = 0
                self.got_packet(channel, cmd, data)
            else:
                break