how to use a test with expecting failure

gistfile1.py

class NotImplementedToExpectedFailure:
    def run(self, result=None):
        # Override the run method to inject the "expectingFailure" marker
        # when the test case runs.
        if self._testMethodName in getattr(self, 'not_implemented', []):
            # Mark 'expecting failure' on class. It will only be applicable
            # for this specific run.
            method = getattr(self, self._testMethodName)
            wrapper = lambda *args, **kwargs: method(*args, **kwargs)
            wrapper.__unittest_expecting_failure__ = True
            setattr(self, self._testMethodName, wrapper)
        return super().run(result=result)

class BinaryBoolOperationTests(NotImplementedToExpectedFailure):

    not_implemented = [
        'test_add_class'
    ]
    
    def test_add_class(self):
        pass
    
    def test_add_complex(self):
        pass