def _get_wrapped_metric(
    func: Callable[..., METRIC_OUTPUT_TYPE], n_wrappers: int = 2
) -> Callable[..., METRIC_OUTPUT_TYPE]:
    """Returns the inner metric function `func` which bypasses the decorators `multi_ts_support` and
    `multivariate_support`. It significantly decreases process time compared to calling `func` directly.
    Only use this to compute a pre-defined metric within the scope of another metric.
    """
    if not 2 <= n_wrappers <= 3:
        raise_log(
            NotImplementedError("Only 2-3 wrappers are currently supported"),
            logger=logger,
        )
    if n_wrappers == 2:
        return func.__wrapped__.__wrapped__
    else:
        return func.__wrapped__.__wrapped__.__wrapped__
Returns the inner metric function `func` which bypasses the decorators `multi_ts_support` and
    `multivariate_support`. It significantly decreases process time compared to calling `func` directly.
    Only use this to compute a pre-defined metric within the scope of another metric.
    
darts/metrics/metrics.py