def test_early_ignored_attributes(self, pytester: Pytester) -> None:
        """Builtin attributes should be ignored early on, even if
        configuration would otherwise allow them.

        This tests a performance optimization, not correctness, really,
        although it tests PytestCollectionWarning is not raised, while
        it would have been raised otherwise.
        """
        pytester.makeini(
            """
            [pytest]
            python_classes=*
            python_functions=*
        """
        )
        pytester.makepyfile(
            """
            class TestEmpty:
                pass
            test_empty = TestEmpty()
            def test_real():
                pass
        """
        )
        items, rec = pytester.inline_genitems()
        assert rec.ret == 0
        assert len(items) == 1
Builtin attributes should be ignored early on, even if
        configuration would otherwise allow them.

        This tests a performance optimization, not correctness, really,
        although it tests PytestCollectionWarning is not raised, while
        it would have been raised otherwise.
        
testing/python/collect.py