code: def list_channels(self, collection_name, experiment_name):
          
          dont_care = 'image'
          chan = ChannelResource(
              name='', collection_name=collection_name,
              experiment_name=experiment_name, type=dont_care)
          return self._list_resource(chan)
docs: List all channels belonging to the named experiment that is part
          of the named collection.
  
          Args:
              collection_name (string): Name of the parent collection.
              experiment_name (string): Name of the parent experiment.
  
          Returns:
              (list)
  
          Raises:
              requests.HTTPError on failure.