def test_empty(self):
self.assertEqual(negate([[]]), [[]])
def test_negative_numbers(self):
inputs = [[1, -2, 3], [-4, 5, -6], [7, -8, 9]]
outputs = [[-1, 2, -3], [4, -5, 6], [-7, 8, -9]]
self.assertEqual(negate(inputs), outputs)
def test_three_by_two_matrix(self):
inputs = [[1, 2], [3, 4], [5, 6]]
outputs = [[-1, -2], [-3, -4], [-5, -6]]
self.assertEqual(negate(inputs), outputs)
def test_three_by_three_matrix(self):
inputs = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
outputs = [[-1, -2, -3], [-4, -5, -6], [-7, -8, -9]]
self.assertEqual(negate(inputs), outputs)
def test_single_item(self):
self.assertEqual(negate([[5]]), [[-5]])