Gets filename of store on disk

def get_filename(cls):
        """ Gets filename of store on disk """
        config_home = os.environ.get("XDG_CONFIG_HOME", "~/.config")
        config_home = os.path.expanduser(config_home)

        base_path = os.path.join(config_home, "PyPump")
        if not os.path.isdir(base_path):
            os.makedirs(base_path)

        return os.path.join(base_path, "credentials.json")