def test_cofactor(self) -> None:
        a = Matrix([[1, 2, 3], [2, 4, 5], [6, 7, 8]], 3, 3)
        cofactors = [[-3, 14, -10], [5, -10, 5], [-2, 1, 0]]
        for x in range(a.height()):
            for y in range(a.width()):
                self.assertEqual(cofactors[x][y], a.cofactor(x, y))