'Test that a cohort cannot be mapped to more than one partition group'

def test_multiple_partition_groups(self):

    self._link_cohort_partition_group(self.first_cohort, self.partition_id, self.group1_id)
    with self.assertRaises(IntegrityError):
        self._link_cohort_partition_group(self.first_cohort, self.partition_id, self.group2_id)
