def METHOD_NAME(self) -> None:
    """Create the data directory to store the postgres data in"""
    if self.db_path:
        if not os.path.exists(self.db_path):
            os.mkdir(self.db_path)
        self._db_path_is_temporary = False
    else:
        self.db_path = tempfile.mkdtemp()
        self._db_path_is_temporary = True