def METHOD_NAME(self):
    dates = numpy.array(['2018-01-01', '2019-03-01', '2020-05-01'],
                        dtype='datetime64[ns]')
    assert_equal(numpy.array(['2018-01', '2019-03', '2020-05'],
                             dtype='datetime64[M]'),
                 calendar.month_and_year(dates))