def test_iadd(self, evt):
        rval = event.ReturnValue(append_events=[evt])
        rval2 = event.ReturnValue(eat=True, append_events=[evt])
        rset = event.ResultSet()

        rset += rval
        rset += rval2
        rset += None
        assert rset.eat
        assert rset.append_events == [evt, evt]
def __init__(
        self,
        dirpath: Optional[Union[str, Path]] = None,
        filename: Optional[str] = None,
    ) -> None:
        self.dirpath = dirpath
        self.filename = filename

        self._output_file: Optional[TextIO] = None
        self._write_stream: Optional[Callable] = None
        self._local_rank: Optional[int] = None
        self._log_dir: Optional[str] = None
        self._stage: Optional[str] = None