code: def __getitem__(self, idx: int):
      pass
  
imports: from abc import ABC, abstractmethod
  from typing import Dict, Optional, Tuple
  import numpy
  from torch.utils.data import Dataset
  from darts import TimeSeries
  from darts.logging import get_logger, raise_if_not
  from .utils import CovariateType
label_desc: Use image node_id 3 for calling the TrainingDataset obj's underlying member method code with example usage: obj.__getitem__(idx) without return types