def test_series_agg_multikey():
    ts = tm.makeTimeSeries()
    grouped = ts.groupby([(lambda x: x.year), (lambda x: x.month)])
    result = grouped.agg(np.sum)
    expected = grouped.sum()
    tm.assert_series_equal(result, expected)
def test_series_agg_multikey():
    ts = tm.makeTimeSeries()
    grouped = ts.groupby([(lambda x: x.year), (lambda x: x.month)])
    result = grouped.agg(np.sum)
    expected = grouped.sum()
    tm.assert_series_equal(result, expected)