docs: def iterkeys(self, match=None, count=1):
          """Return an iterator over the db's keys.
          ``match`` allows for filtering the keys by pattern.
          ``count`` allows for hint the minimum number of returns.
  
          >>> dc = Dictator()
          >>> dc['1'] = 'abc'
          >>> dc['2'] = 'def'
          >>> dc['3'] = 'ghi'
          >>> itr = dc.iterkeys()
          >>> type(itr)
          <type 'generator'>
          >>> list(reversed([item for item in itr]))
          ['1', '2', '3']
          >>> dc.clear()
  
          :param match: pattern to filter keys
          :type match: str
          :param count: minimum number of returns
          :type count: int
          :return: iterator over key.
          :rtype: generator
          """
          logger.debug('call iterkeys %s', match)
          if match is None:
              match = '*'
          for key in self._redis.scan_iter(match=match, count=count):
              yield key