Stat object metadata

        :param container: container name (Container is equivalent to
                          Bucket term in Amazon).
        :param obj: object name (Object is equivalent to
                    Key term in Amazon).

def stat_object(self, container, obj):
        """Stat object metadata

        :param container: container name (Container is equivalent to
                          Bucket term in Amazon).
        :param obj: object name (Object is equivalent to
                    Key term in Amazon).
        """
        LOG.debug('stat_object() with %s is success.', self.driver)
        return self.driver.stat_object(container, obj)