How to use the ceilometer.openstack.common.gettextutils._LE function in ceilometer

data = None
                pre_upgrade = getattr(
                    self, "_pre_upgrade_%03d" % version, None)
                if pre_upgrade:
                    data = pre_upgrade(engine)

            self.migration_api.upgrade(engine, self.REPOSITORY, version)
            self.assertEqual(version,
                             self.migration_api.db_version(engine,
                                                           self.REPOSITORY))
            if with_data:
                check = getattr(self, "_check_%03d" % version, None)
                if check:
                    check(engine, data)
        except Exception:
            LOG.error(_LE("Failed to migrate to version %(version)s "
                          "on engine %(engine)s") % {'version': version,
                                                     'engine': engine})
            raise

def release(self):
        try:
            self.unlock()
            self.lockfile.close()
            LOG.debug('Released file lock "%s"', self.fname)
        except IOError:
            LOG.exception(_LE("Could not release the acquired lock `%s`"),
                          self.fname)

def _connect_error(exc):
            log_info = {'topic': topic, 'err_str': str(exc)}
            LOG.error(_LE("Failed to declare consumer for topic '%(topic)s': "
                      "%(err_str)s") % log_info)

try:
            os.makedirs(ipc_dir)
        except os.error:
            if not os.path.isdir(ipc_dir):
                with excutils.save_and_reraise_exception():
                    LOG.error(_LE("Required IPC directory does not exist at"
                                  " %s") % (ipc_dir, ))
        try:
            self.register(consumption_proxy,
                          consume_in,
                          zmq.PULL)
        except zmq.ZMQError:
            if os.access(ipc_dir, os.X_OK):
                with excutils.save_and_reraise_exception():
                    LOG.error(_LE("Permission denied to IPC directory at"
                                  " %s") % (ipc_dir, ))
            with excutils.save_and_reraise_exception():
                LOG.error(_LE("Could not create ZeroMQ receiver daemon. "
                              "Socket may already be in use."))

        super(ZmqProxy, self).consume_in_thread()

def wrapper(*args, **kwargs):
            next_interval = self.retry_interval
            remaining = self.max_retries

            while True:
                try:
                    return f(*args, **kwargs)
                except exception.DBConnectionError as e:
                    if remaining == 0:
                        LOG.exception(_LE('DB exceeded retry limit.'))
                        raise exception.DBError(e)
                    if remaining != -1:
                        remaining -= 1
                        LOG.exception(_LE('DB connection error.'))
                    # NOTE(vsergeyev): We are using patched time module, so
                    #                  this effectively yields the execution
                    #                  context to another green thread.
                    time.sleep(next_interval)
                    if self.inc_retry_interval:
                        next_interval = min(
                            next_interval * 2,
                            self.max_retry_interval
                        )

for f in self.subscriptions:
                try:
                    self.sock.setsockopt(zmq.UNSUBSCRIBE, f)
                except Exception:
                    pass
            self.subscriptions = []

        try:
            # Default is to linger
            self.sock.close()
        except Exception:
            # While this is a bad thing to happen,
            # it would be much worse if some of the code calling this
            # were to fail. For now, lets log, and later evaluate
            # if we can safely raise here.
            LOG.error(_LE("ZeroMQ socket could not be closed."))
        self.sock = None

if self.max_retries and attempt == self.max_retries:
                msg = _('Unable to connect to AMQP server on '
                        '%(hostname)s:%(port)d after %(max_retries)d '
                        'tries: %(err_str)s') % log_info
                LOG.error(msg)
                raise rpc_common.RPCException(msg)

            if attempt == 1:
                sleep_time = self.interval_start or 1
            elif attempt > 1:
                sleep_time += self.interval_stepping
            if self.interval_max:
                sleep_time = min(sleep_time, self.interval_max)

            log_info['sleep_time'] = sleep_time
            LOG.error(_LE('AMQP server on %(hostname)s:%(port)d is '
                          'unreachable: %(err_str)s. Trying again in '
                          '%(sleep_time)d seconds.') % log_info)
            time.sleep(sleep_time)

def _error_callback(exc):
            log_info = {'topic': topic, 'err_str': str(exc)}
            LOG.exception(_LE("Failed to publish message to topic "
                          "'%(topic)s': %(err_str)s") % log_info)