docs: def delete(self, layer, items):
          """
          Delete items in model.
          """
          # Use edit to get the layer obj containing item
          items = _listify(items)  # make items a list if it's not
          layer_obj = self.edit(layer, dict.fromkeys(items), delete=True)
          for k in items:
              if k in layer_obj.layer:
                  layer_obj.delete(k)
              else:
                  raise AttributeError('item %s missing from layer %s' %
                                       (k, layer))