How to use the gunicorn.util function in gunicorn

self.cfg, self.log)
        self.cfg.pre_fork(self, worker)
        pid = os.fork()
        if pid != 0:
            worker.pid = pid
            self.WORKERS[pid] = worker
            return pid

        # Do not inherit the temporary files of other workers
        for sibling in self.WORKERS.values():
            sibling.tmp.close()

        # Process Child
        worker.pid = os.getpid()
        try:
            util._setproctitle("worker [%s]" % self.proc_name)
            self.log.info("Booting worker with pid: %s", worker.pid)
            self.cfg.post_fork(self, worker)
            worker.init_process()
            sys.exit(0)
        except SystemExit:
            raise
        except AppImportError as e:
            self.log.debug("Exception while loading the application",
                           exc_info=True)
            print("%s" % e, file=sys.stderr)
            sys.stderr.flush()
            sys.exit(self.APP_LOAD_ERROR)
        except:
            self.log.exception("Exception in worker process")
            if not worker.booted:
                sys.exit(self.WORKER_BOOT_ERROR)

    @property
    def worker_class(self):
        uri = self.settings['worker_class'].get()

        ## are we using a threaded worker?
        is_sync = uri.endswith('SyncWorker') or uri == 'sync'
        if is_sync and self.threads > 1:
            uri = "gunicorn.workers.gthread.ThreadWorker"

        worker_class = util.load_class(uri)
        if hasattr(worker_class, "setup"):
            worker_class.setup()
        return worker_class

def _sock_type(addr):
    if isinstance(addr, tuple):
        if util.is_ipv6(addr[0]):
            sock_type = TCP6Socket
        else:
            sock_type = TCPSocket
    elif isinstance(addr, (str, bytes)):
        sock_type = UnixSocket
    else:
        raise TypeError("Unable to create socket from: %r" % addr)
    return sock_type

def bind(self, sock):
        old_umask = os.umask(self.conf.umask)
        sock.bind(self.cfg_addr)
        util.chown(self.cfg_addr, self.conf.uid, self.conf.gid)
        os.umask(old_umask)

with self.timeout_ctx():
                            req = next(parser)
                        if not req:
                            break
                        if req.proxy_protocol_info:
                            proxy_protocol_info = req.proxy_protocol_info
                        else:
                            req.proxy_protocol_info = proxy_protocol_info
                        self.handle_request(listener_name, req, client, addr)
            except http.errors.NoMoreData as e:
                self.log.debug("Ignored premature client disconnection. %s", e)
            except StopIteration as e:
                self.log.debug("Closing connection. %s", e)
            except ssl.SSLError:
                # pass to next try-except level
                util.reraise(*sys.exc_info())
            except EnvironmentError:
                # pass to next try-except level
                util.reraise(*sys.exc_info())
            except Exception as e:
                self.handle_error(req, client, addr, e)
        except ssl.SSLError as e:
            if e.args[0] == ssl.SSL_ERROR_EOF:
                self.log.debug("ssl connection closed")
                client.close()
            else:
                self.log.debug("Error processing SSL request.")
                self.handle_error(req, client, addr, e)
        except EnvironmentError as e:
            if e.errno not in (errno.EPIPE, errno.ECONNRESET):
                self.log.exception("Socket error processing request.")
            else:

if cfg.accesslog is not None:
            self._set_handler(self.access_log, cfg.accesslog,
                fmt=logging.Formatter(self.access_fmt), stream=sys.stdout)

        # set syslog handler
        if cfg.syslog:
            self._set_syslog_handler(
                self.error_log, cfg, self.syslog_fmt, "error"
            )
            if not cfg.disable_redirect_access_to_syslog:
                self._set_syslog_handler(
                    self.access_log, cfg, self.syslog_fmt, "access"
                )

        if dictConfig is None and cfg.logconfig_dict:
            util.warn("Dictionary-based log configuration requires "
                      "Python 2.7 or above.")

        if dictConfig and cfg.logconfig_dict:
            config = CONFIG_DEFAULTS.copy()
            config.update(cfg.logconfig_dict)
            try:
                dictConfig(config)
            except (
                    AttributeError,
                    ImportError,
                    ValueError,
                    TypeError
            ) as exc:
                raise RuntimeError(str(exc))
        elif cfg.logconfig:
            if os.path.exists(cfg.logconfig):

raise TypeError('%r is not a string' % name)

            if HEADER_RE.search(name):
                raise InvalidHeaderName('%r' % name)

            if not isinstance(value, str):
                raise TypeError('%r is not a string' % value)

            if HEADER_VALUE_RE.search(value):
                raise InvalidHeader('%r' % value)

            value = value.strip()
            lname = name.lower().strip()
            if lname == "content-length":
                self.response_length = int(value)
            elif util.is_hoppish(name):
                if lname == "connection":
                    # handle websocket
                    if value.lower().strip() == "upgrade":
                        self.upgrade = True
                elif lname == "upgrade":
                    if value.lower().strip() == "websocket":
                        self.headers.append((name.strip(), value))

                # ignore hopbyhop headers
                continue
            self.headers.append((name.strip(), value))

def load_wsgiapp(self):
        return util.import_app(self.app_uri)