How to use the wsgidav.compat.StringIO function in WsgiDAV

def setUp(self):
        # We add handlers that store root- and base-logger output
        self.rootBuffer = StringIO()
        rootLogger = logging.getLogger()
        self.prevRootLogLevel = rootLogger.getEffectiveLevel()
        self.rootLogHandler = logging.StreamHandler(self.rootBuffer)
        rootLogger.addHandler(self.rootLogHandler)

        self.baseBuffer = StringIO()
        baseLogger = logging.getLogger(BASE_LOGGER_NAME)
        self.prevBaseLogLevel = baseLogger.getEffectiveLevel()
        self.baseLogHandler = logging.StreamHandler(self.baseBuffer)
        baseLogger.addHandler(self.baseLogHandler)

def setUp(self):
        # We add handlers that store root- and base-logger output
        self.rootBuffer = StringIO()
        rootLogger = logging.getLogger()
        self.prevRootLogLevel = rootLogger.getEffectiveLevel()
        self.rootLogHandler = logging.StreamHandler(self.rootBuffer)
        rootLogger.addHandler(self.rootLogHandler)

        self.baseBuffer = StringIO()
        baseLogger = logging.getLogger(BASE_LOGGER_NAME)
        self.prevBaseLogLevel = baseLogger.getEffectiveLevel()
        self.baseLogHandler = logging.StreamHandler(self.baseBuffer)
        baseLogger.addHandler(self.baseLogHandler)

# We have there environment, now invoke the application
            _logger.debug("runWSGIApp application()...")
            result = application(env, self.wsgiStartResponse)
            try:
                for data in result:
                    if data:
                        self.wsgiWriteData(data)
                    else:
                        _logger.debug("runWSGIApp empty data")
            finally:
                _logger.debug("runWSGIApp finally.")
                if hasattr(result, "close"):
                    result.close()
        except Exception:
            _logger.debug("runWSGIApp caught exception...")
            errorMsg = compat.StringIO()
            traceback.print_exc(file=errorMsg)
            logging.error(errorMsg.getvalue())
            if not self.wsgiSentHeaders:
                self.wsgiStartResponse(
                    "500 Server Error", [("Content-type", "text/html")]
                )
            self.wsgiWriteData(SERVER_ERROR)

        if not self.wsgiSentHeaders:
            # GC issue 29 sending one byte, when content-length is '0' seems wrong
            # We must write out something!
            #            self.wsgiWriteData (" ")
            self.wsgiWriteData(b"")
        return

def get_content(self):
        return compat.StringIO(self.content)

def get_content(self):
        """Open content as a stream for reading.

        See DAVResource.get_content()
        """
        filestream = compat.StringIO()

        tableName, primKey = self.provider._split_path(self.path)
        if primKey is not None:
            conn = self.provider._init_connection()
            listFields = self.provider._get_field_list(conn, tableName)
            csvwriter = csv.DictWriter(filestream, listFields, extrasaction="ignore")
            dictFields = {}
            for field_name in listFields:
                dictFields[field_name] = field_name
            csvwriter.writerow(dictFields)

            if primKey == "_ENTIRE_CONTENTS":
                cursor = conn.cursor(MySQLdb.cursors.DictCursor)
                cursor.execute("SELECT * from " + self.provider._db + "." + tableName)
                result_set = cursor.fetchall()
                for row in result_set:

def get_content(self):
        """Open content as a stream for reading.

        See DAVResource.get_content()
        """
        assert not self.is_collection
        d = self.fctx.data()
        return compat.StringIO(d)

def get_content(self):
        html = "<pre>" + pformat(self.doc) + "</pre>"
        return compat.StringIO(html.encode("utf8"))

def element_content_as_string(element):
    """Serialize etree.Element.

    Note: element may contain more than one child or only text (i.e. no child
          at all). Therefore the resulting string may raise an exception, when
          passed back to etree.XML().
    """
    if len(element) == 0:
        return element.text or ""  # Make sure, None is returned as ''
    stream = compat.StringIO()
    for childnode in element:
        stream.write(xml_to_bytes(childnode, pretty_print=False) + "\n")
        # print(xml_to_bytes(childnode, pretty_print=False), file=stream)
    s = stream.getvalue()
    stream.close()
    return s