def _check_copy(self, test, expect):
        f = FrameSet(test)
        r = f.copy()
        self.assertIsNot(f, r)
        self.assertEqual(f, r)
return the id of intervals intersecting with [istar,iend] at each of the discontinuity points
dataset/ETHPy150Open sqlboy/fileseq/test/run.py/TestFrameSet._check_copy--crossover with--dataset/ETHPy150Open fp7-ofelia/ocf/optin_manager/src/python/openflow/optin_manager/flowspace/helper.py/Intervals.get_intersections