code: def rmsse(y_true, y_pred, y_train, sp):
      """Wrapper for sktime metrics"""
      return mean_squared_scaled_error(
          y_true=_check_series(y_true),
          y_pred=_check_series(y_pred),
          sp=sp,
          y_train=_check_series(y_train),
          square_root=True,
      )
  
imports: from typing import Any, Dict, Optional, Union
  import numpy
  import pandas
  from sklearn import metrics
  from sklearn.metrics._scorer import _BaseScorer
  from sktime.performance_metrics.forecasting._functions import mean_absolute_percentage_error, mean_absolute_scaled_error, mean_squared_scaled_error
  import pycaret.internal.metrics
  from pycaret.containers.metrics.base_metric import MetricContainer
label_desc: Use image node_id 4 for calling a global function with example usage: rmsse(y_true, y_pred, y_train, sp) and returns: mean_squared_scaled_error