| from contextlib import ExitStack, contextmanager | |
| from typing import ContextManager, Generator, TypeVar | |
| _T = TypeVar("_T", covariant=True) | |
| class CommandContextMixIn: | |
| def __init__(self) -> None: | |
| super().__init__() | |
| self._in_main_context = False | |
| self._main_context = ExitStack() | |
| def main_context(self) -> Generator[None, None, None]: | |
| assert not self._in_main_context | |
| self._in_main_context = True | |
| try: | |
| with self._main_context: | |
| yield | |
| finally: | |
| self._in_main_context = False | |
| def enter_context(self, context_provider: ContextManager[_T]) -> _T: | |
| assert self._in_main_context | |
| return self._main_context.enter_context(context_provider) | |