def METHOD_NAME(self):
    with self._isolate_repo("single_tool") as f:
        upload_command = ["shed_upload", "--force_repository_creation"]
        upload_command.extend(self._shed_args())
        self._check_exit_code(upload_command)
        io.write_file(
            join(f, "related_file"),
            "A related non-tool file (modified).\n",
        )
        self._check_diff(f, True)
        self._check_diff(f, False)