code: def __getstate__(self):
      self_dict = self.__dict__.copy()
      del self_dict["pool"]
      return self_dict
  
imports: import collections
  from abc import ABC, abstractmethod
  import numpy
  from scipy._lib._util import MapWrapper
label_desc: Use image node_id 3 for calling the VertexCacheField obj's underlying member method code with example usage: obj.__getstate__() and returns: self_dict