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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def config_updated_since(self, sentry_unit, filename, mtime, sleep_time=20, retry_count=30, retry_sleep_time=10):
 """Check if file was modified after a given time. Args: sentry_unit (sentry):
 The sentry unit to check the file mtime on filename (string):
 The file to check mtime of mtime (float):
 The epoch time to check against sleep_time (int):
 Initial sleep time (s) before looking for file retry_sleep_time (int):
 Time (s) to sleep between retries retry_count (int):
 If file is not found, how many times to retry Returns: bool: True if file was modified more recently than mtime, False if file was modified before mtime, or if file not found. """

        unit_name = sentry_unit.info['unit_name']
        self.log.debug('Checking that %s updated since %s on '
                       '%s' % (filename, mtime, unit_name))
        time.sleep(sleep_time)
        file_mtime = None
        tries = 0
        while tries <= retry_count and not file_mtime:
            try:
                file_mtime = self._get_file_mtime(sentry_unit, filename)
                self.log.debug('Attempt {} to get {} file mtime on {} '
                               'OK'.format(tries, filename, unit_name))
            except IOError as e:
                # NOTE(beisner) - race avoidance, file may not exist yet.
                # https://bugs.launchpad.net/charm-helpers/+bug/1474030
                self.log.debug('Attempt {} to get {} file mtime on {} '
                               'failed\n{}'.format(tries, filename,
                                                   unit_name, e))
                time.sleep(retry_sleep_time)
                tries += 1

        if not file_mtime:
            self.log.warn('Could not determine file mtime, assuming '
                          'file does not exist')
            return False

        if file_mtime >= mtime:
            self.log.debug('File mtime is newer than provided mtime '
                           '(%s >= %s) on %s (OK)' % (file_mtime,
                                                      mtime, unit_name))
            return True
        else:
            self.log.warn('File mtime is older than provided mtime'
                          '(%s < on %s) on %s' % (file_mtime,
                                                  mtime, unit_name))
            return False