How to use the mobly.utils function in mobly

if begin_time is None:
            begin_time = mobly_logger.get_log_file_timestamp()

        new_br = True
        try:
            stdout = self.adb.shell('bugreportz -v').decode('utf-8')
            # This check is necessary for builds before N, where adb shell's ret
            # code and stderr are not propagated properly.
            if 'not found' in stdout:
                new_br = False
        except adb.AdbError:
            new_br = False

        if destination is None:
            destination = os.path.join(self.log_path, 'BugReports')
        br_path = utils.abs_path(destination)
        utils.create_dir(br_path)
        filename = self.generate_filename(prefix, str(begin_time), 'txt')
        if new_br:
            filename = filename.replace('.txt', '.zip')
        full_out_path = os.path.join(br_path, filename)
        # in case device restarted, wait for adb interface to return
        self.wait_for_boot_completion()
        self.log.debug('Start taking bugreport.')
        if new_br:
            out = self.adb.shell('bugreportz', timeout=timeout).decode('utf-8')
            if not out.startswith('OK'):
                raise DeviceError(self, 'Failed to take bugreport: %s' % out)
            br_out_path = out.split(':')[1].strip()
            self.adb.pull([br_out_path, full_out_path])
        else:
            # shell=True as this command redirects the stdout to a local file

"""Restores the sl4a after device got disconnected.

        Instead of creating new instance of the client:
          - Uses the given port (or find a new available host_port if none is
            given).
          - Tries to connect to remote server with selected port.

        Args:
          port: If given, this is the host port from which to connect to remote
              device port. If not provided, find a new available port as host
              port.

        Raises:
            AppRestoreConnectionError: When the app was not able to be started.
        """
        self.host_port = port or utils.get_available_host_port()
        self._retry_connect()
        self.ed = self._start_event_client()

def _load_config_file(path):
    """Loads a test config file.

    The test config file has to be in YAML format.

    Args:
        path: A string that is the full path to the config file, including the
            file name.

    Returns:
        A dict that represents info in the config file.
    """
    with io.open(utils.abs_path(path), 'r', encoding='utf-8') as f:
        conf = yaml.safe_load(f)
        return conf

def _test_end(self, result, e):
        """Marks the end of the test logic.

        Args:
            result: One of the TEST_RESULT enums in TestResultEnums.
            e: A test termination signal (usually an exception object). It can
                be any exception instance or of any subclass of
                mobly.signals.TestSignal.
        """
        if self.begin_time is not None:
            self.end_time = utils.get_current_epoch_time()
        self.result = result
        if e:
            self.termination_signal = ExceptionRecord(e)