How to use the wsgidav.util.get_rfc1123_time function in WsgiDAV

def send_basic_auth_response(self, environ, start_response):
        realm = self.domain_controller.get_domain_realm(environ["PATH_INFO"], environ)
        _logger.debug("401 Not Authorized for realm '{}' (basic)".format(realm))
        wwwauthheaders = 'Basic realm="' + realm + '"'

        body = compat.to_bytes(self.error_message_401)
        start_response(
            "401 Not Authorized",
            [
                ("WWW-Authenticate", wwwauthheaders),
                ("Content-Type", "text/html"),
                ("Content-Length", str(len(body))),
                ("Date", util.get_rfc1123_time()),
            ],
        )
        return [body]

if name == "{DAV:}creationdate" and self.get_creation_date() is not None:
                # Note: uses RFC3339 format (ISO 8601)
                return util.get_rfc3339_time(self.get_creation_date())
            elif name == "{DAV:}getcontenttype" and self.get_content_type() is not None:
                return self.get_content_type()
            elif name == "{DAV:}resourcetype":
                if self.is_collection:
                    resourcetypeEL = etree.Element(name)
                    etree.SubElement(resourcetypeEL, "{DAV:}collection")
                    return resourcetypeEL
                return ""
            elif (
                name == "{DAV:}getlastmodified" and self.get_last_modified() is not None
            ):
                # Note: uses RFC1123 format
                return util.get_rfc1123_time(self.get_last_modified())
            elif (
                name == "{DAV:}getcontentlength"
                and self.get_content_length() is not None
            ):
                # Note: must be a numeric string
                return str(self.get_content_length())
            elif name == "{DAV:}getetag" and self.get_etag() is not None:
                return self.get_etag()
            elif name == "{DAV:}displayname" and self.get_display_name() is not None:
                return self.get_display_name()

            # Unsupported, no persistence available, or property not found
            raise DAVError(HTTP_NOT_FOUND)

        # Dead property
        pm = self.provider.prop_manager

# obtain_content_ranges supports more than one range in case the above
            # behaviour changes in future
            (range_start, range_end, range_length) = list_ranges[0]
        else:
            (range_start, range_end, range_length) = (0, filesize - 1, filesize)

        # Content Processing
        mimetype = res.get_content_type()  # provider.get_content_type(path)

        response_headers = []
        if res.support_content_length():
            # Content-length must be of type string
            response_headers.append(("Content-Length", str(range_length)))
        if res.support_modified():
            response_headers.append(
                ("Last-Modified", util.get_rfc1123_time(last_modified))
            )
        response_headers.append(("Content-Type", mimetype))
        response_headers.append(("Date", util.get_rfc1123_time()))
        if res.support_etag():
            response_headers.append(("ETag", '"{}"'.format(entitytag)))

        if res.support_ranges():
            response_headers.append(("Accept-Ranges", "bytes"))

        if "response_headers" in environ["wsgidav.config"]:
            customHeaders = environ["wsgidav.config"]["response_headers"]
            for header, value in customHeaders:
                response_headers.append((header, value))

        res.finalize_headers(environ, response_headers)

# Skip ignore patterns
            ignore = False
            for pat in ignore_patterns:
                if fnmatch(entry["display_name"], pat):
                    ignored_list.append(entry["display_name"])
                    # _logger.debug("Ignore {}".format(entry["display_name"]))
                    ignore = True
                    break
            if ignore:
                continue
            #
            last_modified = entry.get("last_modified")
            if last_modified is None:
                entry["str_modified"] = ""
            else:
                entry["str_modified"] = util.get_rfc1123_time(last_modified)

            entry["str_size"] = "-"
            if not entry.get("is_collection"):
                content_length = entry.get("content_length")
                if content_length is not None:
                    entry["str_size"] = util.byte_number_string(content_length)

            rows.append(entry)
        if ignored_list:
            _logger.debug(
                "Dir browser ignored {} entries: {}".format(
                    len(ignored_list), ignored_list
                )
            )

        # sort

"""
        @see http://www.webdav.org/specs/rfc4918.html#HEADER_DAV
        """
        path = environ["PATH_INFO"]
        provider = self._davProvider
        res = provider.get_resource_inst(path, environ)

        dav_compliance_level = "1,2"
        if provider is None or provider.is_readonly() or provider.lock_manager is None:
            dav_compliance_level = "1"

        headers = [
            ("Content-Type", "text/html"),
            ("Content-Length", "0"),
            ("DAV", dav_compliance_level),
            ("Date", util.get_rfc1123_time()),
        ]

        if path == "/":
            path = "*"  # Hotfix for WinXP

        if path == "*":
            # Answer HTTP 'OPTIONS' method on server-level.
            # From RFC 2616
            # If the Request-URI is an asterisk ("*"), the OPTIONS request is
            # intended to apply to the server in general rather than to a specific
            # resource. Since a server's communication options typically depend on
            # the resource, the "*" request is only useful as a "ping" or "no-op"
            # type of method; it does nothing beyond allowing the client to test the
            # capabilities of the server. For example, this can be used to test a
            # proxy for HTTP/1.1 compliance (or lack thereof).
            start_response("200 OK", headers)

)

        _logger.debug(
            "401 Not Authorized for realm '{}' (digest): {}".format(
                realm, wwwauthheaders
            )
        )

        body = compat.to_bytes(self.error_message_401)
        start_response(
            "401 Not Authorized",
            [
                ("WWW-Authenticate", wwwauthheaders),
                ("Content-Type", "text/html"),
                ("Content-Length", str(len(body))),
                ("Date", util.get_rfc1123_time()),
            ],
        )
        return [body]

else:
            (range_start, range_end, range_length) = (0, filesize - 1, filesize)

        # Content Processing
        mimetype = res.get_content_type()  # provider.get_content_type(path)

        response_headers = []
        if res.support_content_length():
            # Content-length must be of type string
            response_headers.append(("Content-Length", str(range_length)))
        if res.support_modified():
            response_headers.append(
                ("Last-Modified", util.get_rfc1123_time(last_modified))
            )
        response_headers.append(("Content-Type", mimetype))
        response_headers.append(("Date", util.get_rfc1123_time()))
        if res.support_etag():
            response_headers.append(("ETag", '"{}"'.format(entitytag)))

        if res.support_ranges():
            response_headers.append(("Accept-Ranges", "bytes"))

        if "response_headers" in environ["wsgidav.config"]:
            customHeaders = environ["wsgidav.config"]["response_headers"]
            for header, value in customHeaders:
                response_headers.append((header, value))

        res.finalize_headers(environ, response_headers)

        if ispartialranges:
            # response_headers.append(("Content-Ranges", "bytes " + str(range_start) + "-" +
            #    str(range_end) + "/" + str(range_length)))

("Date", util.get_rfc1123_time()),
                    ],
                )
                return [res]

            context = self._get_context(environ, dav_res)

            res = self.template.render(**context)
            res = compat.to_bytes(res)
            start_response(
                "200 OK",
                [
                    ("Content-Type", "text/html"),
                    ("Content-Length", str(len(res))),
                    ("Cache-Control", "private"),
                    ("Date", util.get_rfc1123_time()),
                ],
            )
            return [res]

        return self.next_app(environ, start_response)