code: def add_image(self, batch_id, image_id, image_properties=None):
      
      if batch_id not in self._data:
        raise KeyError('Batch with ID "{0}" does not exist'.format(batch_id))
      if image_properties is None:
        image_properties = {}
      if not isinstance(image_properties, dict):
        raise ValueError('image_properties has to be dict, however it was: '
                         + str(type(image_properties)))
      self._data[batch_id]['images'][image_id] = image_properties.copy()
docs: Adds image to given batch.