def ensure_working_tree(self):
if not self.supports_working_tree:<EOL><INDENT>raise MissingWorkingTreeError(compact("""<STR_LIT>""", friendly_name=self.friendly_name, directory=format_path(self.local)))<EOL><DEDENT>
Make sure the local repository has working tree support.

:raises: :exc:`~vcs_repo_mgr.exceptions.MissingWorkingTreeError` when
         the local repository doesn't support a working tree.