magnitude should be a property and not a method

I have passed all tests except for the magnitude test and am getting the error shown below. My magnitude function works in my personal test, but the error seems to have an issue with the test input. Can anyone provide some insight?

Traceback (most recent call last):
File "/runner/frameworks/python/cw-2.py", line 111, in wrapper
func()
File "main.py", line 104, in _
test.assert_approx_equals(Vector(examples[0][:]).magnitude, 3.741, 0.001)
File "/runner/frameworks/python/cw-2.py", line 84, in assert_approx_equals
div = max(abs(actual), abs(expected), 1)
TypeError: bad operand type for abs(): 'method'