code: def channel_history(current):
      
      current.output = {
          'status': 'OK',
          'code': 201,
          'messages': []
      }
  
      for msg in list(Message.objects.filter(channel_id=current.input['channel_key'],
                                        updated_at__lte=current.input['timestamp'])[:20]):
          current.output['messages'].insert(0, msg.serialize(current.user))
      # FIXME: looks like  pyoko's __lt is broken
      # TODO: convert lte to lt and remove this block, when __lt filter fixed
      if current.output['messages']:
          current.output['messages'].pop(-1)
docs: Get old messages for a channel. 20 messages per request
  
          .. code-block:: python
  
              #  request:
                  {
                  'view':'_zops_channel_history,
                  'channel_key': key,
                  'timestamp': datetime, # timestamp data of oldest shown message
                  }
  
              #  response:
                  {
                  'messages': [MSG_DICT, ],
                  'status': 'OK',
                  'code': 200
                  }