def __init__(self, writers, period=20):
        """
        Args:
            writers (list[EventWriter]): a list of EventWriter objects
            period (int):
        """
        self._writers = writers
        for w in writers:
            assert isinstance(w, EventWriter), w
        self._period = period

        Args:
            writers (list[EventWriter]): a list of EventWriter objects
            period (int):
        
EVA-01/det/detectron2/engine/hooks.py