def METHOD_NAME(self):
    symdiff = self.c1 ^ self.c2
    mask = symdiff.to_mask()
    assert_allclose(mask.data[:, 7], [0, 0, 0, 0, 0, 0, 0, 0, 0])
    assert_allclose(mask.data[:, 6], [0, 1, 1, 1, 1, 1, 1, 1, 0])