class_docstr: a simple unbounded cache backed by a dictionary
class_docstr_tok: ["a","simple","unbounded","cache","backed","by","a","dictionary"]
code: def invalidate(self, key):
      try:
          del self._data[key]
      except KeyError:
          pass
  
imports: from abc import abstractmethod
  from abc import ABCMeta
  import threading
  import time
  import uuid
  import inspect
label_desc: Use image node_id 4 for calling the UnboundedCache obj's underlying member method code with example usage: obj.invalidate(key) without return types