How to use the spleeter.utils.logging.Formatter function in spleeter

def get_logger():
    """ Returns library scoped logger.

    :returns: Library logger.
    """
    if _LoggerHolder.INSTANCE is None:
        formatter = logging.Formatter(_FORMAT)
        handler = logging.StreamHandler()
        handler.setFormatter(formatter)
        logger = logging.getLogger('spleeter')
        logger.addHandler(handler)
        logger.setLevel(logging.INFO)
        _LoggerHolder.INSTANCE = logger
    return _LoggerHolder.INSTANCE