code: def __len__(self) -> int:
      return len(self._keys)
  
file_path: DeepPavlov/deeppavlov/configs/__init__.py
imports: from pathlib import Path
  from typing import Iterator, Dict, Union, Iterable
label_desc: Use image node_id 2 for calling the Struct obj's underlying member method code with example usage: obj.__len__() and returns: len