code: def _incr_decr(self, command, key, value, default, time):
          
          time = time if time >= 0 else self.MAXIMUM_EXPIRE_TIME
          self._send(struct.pack(self.HEADER_STRUCT +
                                 self.COMMANDS[command]['struct'] % len(key),
                                 self.MAGIC['request'],
                                 self.COMMANDS[command]['command'],
                                 len(key),
                                 20, 0, 0, len(key) + 20, 0, 0, value,
                                 default, time, str_to_bytes(key)))
  
          (magic, opcode, keylen, extlen, datatype, status, bodylen, opaque,
           cas, extra_content) = self._get_response()
  
          if status not in (self.STATUS['success'], self.STATUS['server_disconnected']):
              raise MemcachedException('Code: %d Message: %s' % (status, extra_content), status)
          if status == self.STATUS['server_disconnected']:
              return 0
  
          return struct.unpack('!Q', extra_content)[0]
docs: Function which increments and decrements.
  
          :param key: Key's name
          :type key: six.string_types
          :param value: Number to be (de|in)cremented
          :type value: int
          :param default: Default value if key does not exist.
          :type default: int
          :param time: Time in seconds to expire key.
          :type time: int
          :return: Actual value of the key on server
          :rtype: int