code: def __str__(self) -> str:
      formatted_keys = ", ".join(f'"{key}"' for key in self.keys)
      return f"can not match {formatted_keys} to any data class field"
  
imports: from typing import Any, Type, Optional, Set, Dict
label_desc: Use image node_id 2 for calling the UnexpectedDataError obj's underlying member method code with example usage: obj.__str__() and returns: str, formatted_keys, str