def test_no_magic_values(self, pytester: Pytester, keyword: str) -> None:
        """Make sure the tests do not match on magic values,
        no double underscored values, like '__dict__' and '+'.
        """
        p = pytester.makepyfile(
            """
            def test_one(): assert 1
        """
        )

        reprec = pytester.inline_run("-k", keyword, p)
        passed, skipped, failed = reprec.countoutcomes()
        dlist = reprec.getcalls("pytest_deselected")
        assert passed + skipped + failed == 0
        deselected_tests = dlist[0].items
        assert len(deselected_tests) == 1
Make sure the tests do not match on magic values,
        no double underscored values, like '__dict__' and '+'.
        
testing/test_mark.py