code: def key(attr: EdgeAttr) -> Tuple:
      return (
          attr.edge_type,
          attr.layout.value,
          attr.is_sorted,
          attr.size,
      )
  
file_path: pytorch_geometric/torch_geometric/testing/graph_store.py
imports: from typing import Dict, List, Optional, Tuple
  from torch import Tensor
  from torch_geometric.data import EdgeAttr, GraphStore
  from torch_geometric.typing import EdgeTensorType
label_desc: Use image node_id 2 for calling the MyGraphStore obj's underlying member method code with example usage: obj.key(attr) and returns: attr,  attr,  attr,  attr