test_add() TypeError: CalcTest.test_add() missing 1 required positional argument: 'self'

It looks like the error is occurring because the test_add method is missing the 'self' parameter. In Python, all instance methods in a class should have 'self' as the first parameter to reference the instance of the class.

To fix this error, make sure to include 'self' as the first parameter in the test_add method definition. Here is an example of how the test_add method should be defined:

def test_add(self):
    # test logic here

By adding 'self' as the first parameter, the error should be resolved.