code: def next_batch(self, _):
          "Handler for 'Next Batch' button click. Delete all flagged images and renders next batch."
          for img_widget, delete_btn, fp, in self._batch:
              fp = delete_btn.file_path
              if (delete_btn.flagged_for_delete == True):
                  self.delete_image(fp)
                  self._deleted_fns.append(fp)
          self._all_images = self._all_images[self._batch_size:]
          self.empty_batch()
          self.render(f next_batch(self, _):
          "Handler for 'Next Batch' button click. Delete all flagged images and renders next batch."
          for img_widget, delete_btn, fp, in self._batch:
              fp = delete_btn.file_path
              if (delete_btn.flagged_for_delete == True):
                  self.delete_image(fp)
                  self._deleted_fns.append(fp)
          self._all_images = self._all_images[self._batch_size:]
          self.empty_batch()
          self.render()
docs: Handler for 'Next Batch' button click. Delete all flagged images and renders next batch.