code: def flush_all(self, delay=0, noreply=None):
          
          if noreply is None:
              noreply = self.default_noreply
          cmd = b'flush_all ' + six.text_type(delay).encode('ascii')
          if noreply:
              cmd += b' noreply'
          cmd += b'\r\n'
          results = self._misc_cmd([cmd], b'flush_all', noreply)
          if noreply:
              return True
          return results[0] == b'OK'
docs: The memcached "flush_all" command.
  
          Args:
            delay: optional int, the number of seconds to wait before flushing,
                   or zero to flush immediately (the default).
            noreply: optional bool, True to not wait for the reply (defaults to
                     self.default_noreply).
  
          Returns:
            True.