code: def __getitem__(self, idx):
      return super().__getitem__(self.t - idx)
  
file_path: river/river/time_series/test_snarimax.py
imports: from __future__ import annotations
  import calendar
  import math
  import random
  import pytest
  import sympy
  from river import compose, datasets, metrics, time_series
  from river.time_series.snarimax import Differencer
label_desc: Use image node_id 1 for calling the Yt obj's underlying member method code with example usage: obj.__getitem__(idx) and returns: super