def test_using_python_path(self, pytester: Pytester) -> None:
        """
        Dummy modules created by insert_missing_modules should not get in
        the way of modules that could be imported via python path (#9645).
        """
        pytester.makeini(
            """
            [pytest]
            pythonpath = .
            addopts = --import-mode importlib
            """
        )
        pytester.makepyfile(
            **{
                "tests/__init__.py": "",
                "tests/conftest.py": "",
                "tests/subpath/__init__.py": "",
                "tests/subpath/helper.py": "",
                "tests/subpath/test_something.py": """
                import tests.subpath.helper

                def test_something():
                    assert True
                """,
            }
        )
        result = pytester.runpytest()
        result.stdout.fnmatch_lines("*1 passed in*")

        Dummy modules created by insert_missing_modules should not get in
        the way of modules that could be imported via python path (#9645).
        
testing/test_collection.py