(self, op: str, states: Tuple[str, ...])
| 260 | ) |
| 261 | |
| 262 | def _assert_state(self, op: str, states: Tuple[str, ...]) -> None: |
| 263 | assert ( |
| 264 | self._state in states |
| 265 | ), "cannot {} in state {!r}: expected one of {}".format( |
| 266 | op, self._state, ", ".join(states) |
| 267 | ) |
| 268 | |
| 269 | def start(self) -> None: |
| 270 | self._assert_state("start", ("initialized",)) |