How to use the supervisor.compat.as_string function in supervisor

def found_terminator (self):
        """ We only override this to use 'deferring_http_request' class
        instead of the normal http_request class; it sucks to need to override
        this """
        if self.current_request:
            self.current_request.found_terminator()
        else:
            # we convert the header to text to facilitate processing.
            # some of the underlying APIs (such as splitquery)
            # expect text rather than bytes.
            header = as_string(self.in_buffer)
            self.in_buffer = b''
            lines = header.split('\r\n')

            # --------------------------------------------------
            # crack the request header
            # --------------------------------------------------

            while lines and not lines[0]:
                # as per the suggestion of http-1.1 section 4.1, (and
                # Eric Parker ), ignore a leading
                # blank lines (buggy browsers tack it onto the end of
                # POST requests)
                lines = lines[1:]

            if not lines:
                self.close_when_done()

def send(self, data, stdout=sys.stdout):
        resultlen = len(data)
        result = '%s%s\n%s' % (as_string(PEventListenerDispatcher.RESULT_TOKEN_START),
                               str(resultlen),
                               data)
        stdout.write(result)
        stdout.flush()

def kill(self, sig):
        """Send a signal to the subprocess.  This may or may not kill it.

        Return None if the signal was sent, or an error message string
        if an error occurred or if the subprocess is not running.
        """
        now = time.time()
        options = self.config.options

        processname = as_string(self.config.name)
        # If the process is in BACKOFF and we want to stop or kill it, then
        # BACKOFF -> STOPPED.  This is needed because if startretries is a
        # large number and the process isn't starting successfully, the stop
        # request would be blocked for a long time waiting for the retries.
        if self.state == ProcessStates.BACKOFF:
            msg = ("Attempted to kill %s, which is in BACKOFF state." %
                   processname)
            options.logger.debug(msg)
            self.change_state(ProcessStates.STOPPED)
            return None

        if not self.pid:
            msg = ("attempted to kill %s with sig %s but it wasn't running" %
                   (processname, signame(sig)))
            options.logger.debug(msg)
            return msg

        "base64": lambda x: as_string(decodestring(as_bytes(x.text or ""))),
        "param": lambda x: x[0].text,

def signal(self, sig):
        """Send a signal to the subprocess, without intending to kill it.

        Return None if the signal was sent, or an error message string
        if an error occurred or if the subprocess is not running.
        """
        options = self.config.options
        processname = as_string(self.config.name)
        if not self.pid:
            msg = ("attempted to send %s sig %s but it wasn't running" %
                   (processname, signame(sig)))
            options.logger.debug(msg)
            return msg

        options.logger.debug('sending %s (pid %s) sig %s'
                             % (processname,
                                self.pid,
                                signame(sig))
                             )

        self._assertInState(ProcessStates.RUNNING,
                            ProcessStates.STARTING,
                            ProcessStates.STOPPING)

def _spawn_as_parent(self, pid):
        # Parent
        self.pid = pid
        options = self.config.options
        options.close_child_pipes(self.pipes)
        options.logger.info('spawned: \'%s\' with pid %s' % (as_string(self.config.name), pid))
        self.spawnerr = None
        self.delay = time.time() + self.config.startsecs
        options.pidhistory[pid] = self
        return pid

def recv(self, buffersize):
            return as_string(os.read(self.fd, buffersize))

def shutdown_report(self):
        unstopped = []

        for group in self.process_groups.values():
            unstopped.extend(group.get_unstopped_processes())

        if unstopped:
            # throttle 'waiting for x to die' reports
            now = time.time()
            if now > (self.lastshutdownreport + 3): # every 3 secs
                names = [ as_string(p.config.name) for p in unstopped ]
                namestr = ', '.join(names)
                self.options.logger.info('waiting for %s to die' % namestr)
                self.lastshutdownreport = now
                for proc in unstopped:
                    state = getProcessStateDescription(proc.get_state())
                    self.options.logger.blather(
                        '%s state: %s' % (proc.config.name, state))
        return unstopped

def request(self, host, handler, request_body, verbose=0):
        request_body = as_bytes(request_body)
        if not self.connection:
            self.connection = self._get_connection()
            self.headers = {
                "User-Agent" : self.user_agent,
                "Content-Type" : "text/xml",
                "Accept": "text/xml"
                }

            # basic auth
            if self.username is not None and self.password is not None:
                unencoded = "%s:%s" % (self.username, self.password)
                encoded = as_string(encodestring(as_bytes(unencoded)))
                encoded = encoded.replace('\n', '')
                encoded = encoded.replace('\012', '')
                self.headers["Authorization"] = "Basic %s" % encoded

        self.headers["Content-Length"] = str(len(request_body))

        self.connection.request('POST', handler, request_body, self.headers)

        r = self.connection.getresponse()

        if r.status != 200:
            self.connection.close()
            self.connection = None
            raise xmlrpclib.ProtocolError(host + handler,
                                          r.status,
                                          r.reason,

length = 0
                offset = sz - length

            if offset < 0:
                offset = 0
            if length < 0:
                length = 0

            if length == 0:
                data = ''
            else:
                f.seek(offset)
                data = f.read(length)

            offset = sz
            return [as_string(data), offset, overflow]
    except (OSError, IOError):
        return ['', offset, False]