def __init__(
        self,
        dirpath: Optional[Union[str, Path]] = None,
        filename: Optional[str] = None,
        extended: bool = True,
    ) -> None:
        """
        Args:
            dirpath: Directory path for the ``filename``. If ``dirpath`` is ``None`` but ``filename`` is present, the
                ``trainer.log_dir`` (from :class:`~lightning.pytorch.loggers.tensorboard.TensorBoardLogger`)
                will be used.

            filename: If present, filename where the profiler results will be saved instead of printing to stdout.
                The ``.txt`` extension will be used automatically.

            extended: If ``True``, adds extra columns representing number of calls and percentage of total time spent on
                respective action.

        Raises:
            ValueError:
                If you attempt to start an action which has already started, or
                if you attempt to stop recording an action which was never started.
        """
        super().__init__(dirpath=dirpath, filename=filename)
        self.current_actions: dict[str, float] = {}
        self.recorded_durations: dict = defaultdict(list)
        self.extended = extended
        self.start_time = time.monotonic()

        Args:
            dirpath: Directory path for the ``filename``. If ``dirpath`` is ``None`` but ``filename`` is present, the
                ``trainer.log_dir`` (from :class:`~lightning.pytorch.loggers.tensorboard.TensorBoardLogger`)
                will be used.

            filename: If present, filename where the profiler results will be saved instead of printing to stdout.
                The ``.txt`` extension will be used automatically.

            extended: If ``True``, adds extra columns representing number of calls and percentage of total time spent on
                respective action.

        Raises:
            ValueError:
                If you attempt to start an action which has already started, or
                if you attempt to stop recording an action which was never started.
        
src/lightning/pytorch/profilers/simple.py