code: def _get_tensor_size(
      self, attr: TensorAttr
  ) -> Optional[Tuple[int, ...]]:
      tensor = self._get_tensor(attr)
      return tensor.size() if tensor is not None else None
  
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 6 for calling the MyFeatureStore obj's underlying member method code with example usage: obj._get_tensor_size(attr) and returns: unknown