def assert_file_count(self, pattern: str, count: int) -> None:
        """Assert that there are `count` files matching `pattern`."""
        files = sorted(glob.glob(pattern))
        msg = "There should be {} files matching {!r}, but there are these: {}"
        msg = msg.format(count, pattern, files)
        assert len(files) == count, msg
Assert that there are `count` files matching `pattern`.
tests/coveragetest.py