def test_addition_with_nested_lists(): assert addition(1, [1, 2, 4, [3]], 0, [[[[[[4]], 5, 6]]]]) == 26
def test_addition_of_no_number(): assert addition() is None
def test_addition_of_diverse_elements(): assert addition(1, [1, 2, 4, 3], 0) == 11
def test_addition_of_an_array_of_numbers(): assert addition([1, 2, 4, 3]) == 10
def test_addition_of_4_numbers(): assert addition(1, 2, 4, 3) == 10
def test_addition_of_2_numbers(): assert addition(1, 2) == 3
def test_addition_of_1_number(): assert addition(1) == 1