@classmethod
def get_file(cls, url, working_dir):
    """
        Load file from filesystem or s3
        :param url: str
        :param working_dir: str
        :return: str(utf-8)
        """
    if url.lower().startswith('s3://'):
        return cls._s3_get_file(url)
    else:
        return cls._fs_get_file(url, working_dir)
