def select_related(self, *fields):

        if self._fields is not None:
            raise TypeError("Cannot call select_related() after .values() or .values_list()")

        obj = self._clone()
        if fields == (None,):
            obj.query.select_related = False
        elif fields:
            obj.query.add_select_related(fields)
        else:
            obj.query.select_related = True
        return obj
Test the assertion of a tracker accuracy.
dataset/ETHPy150Open django/django/django/db/models/query.py/QuerySet.select_related--crossover with--dataset/ETHPy150Open home-assistant/home-assistant/tests/components/device_tracker/test_owntracks.py/TestDeviceTrackerOwnTracks.assert_tracker_accuracy