code: def key(attr: TensorAttr) -> KeyType:
      return (attr.group_name, attr.attr_name)
  
file_path: pytorch_geometric/torch_geometric/testing/feature_store.py
imports: from typing import Dict, List, Optional, Tuple
  import torch
  from torch import Tensor
  from torch_geometric.data import FeatureStore, TensorAttr
  from torch_geometric.typing import FeatureTensorType
label_desc: Use image node_id 2 for calling the MyFeatureStore obj's underlying member method code with example usage: obj.key(attr) and returns: attr,  attr