def test_filter_when_cutoff_after_end(self):
assert len(
DataSplitter.get_first_n_nanos(self.df, 15 * 10**9)['time']) == 2
def test_filter_when_cutoff_before_end(self):
assert len(DataSplitter.get_first_n_nanos(self.df, 5)['time']) == 1