def test_nth_multi_index(self):
    grouped = self.three_group.groupby(['A', 'B'])
    result = grouped.nth(0)
    expected = grouped.first()
    assert_frame_equal(result, expected)
def test_nth_multi_index(self):
    grouped = self.three_group.groupby(['A', 'B'])
    result = grouped.nth(0)
    expected = grouped.first()
    assert_frame_equal(result, expected)