code: def __repr__(self) -> str:
      mapping = {key: self._mapping[key] for key in self._keys()}
      return f"{self.__class__.__name__}({mapping})"
  
file_path: pytorch_geometric/torch_geometric/data/view.py
imports: from typing import Any, Iterator, List, Mapping, Tuple
label_desc: Use image node_id 4 for calling the MappingView obj's underlying member method code with example usage: obj.__repr__() and returns: self, str, mapping, str