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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def north_arrow(self, north_arrow_path):
 """Set image that will be used as north arrow in reports. :param north_arrow_path: Path to the north arrow image. :type north_arrow_path: str """

        if isinstance(north_arrow_path, str) and os.path.exists(
                north_arrow_path):
            self._north_arrow = north_arrow_path
        else:
            self._north_arrow = default_north_arrow_path()