def delete(self, image_file, delete_thumbnails=True):
if delete_thumbnails:<EOL><INDENT>self.delete_thumbnails(image_file)<EOL><DEDENT>self._delete(image_file.key)<EOL>
Deletes the reference to the ``image_file`` and deletes the references
to thumbnails as well as thumbnail files if ``delete_thumbnails`` is
`True``. Does not delete the ``image_file`` is self.