code: def nodes(self):
      return self._get_all_nodes(self.root)
  
imports: import copy
  from typing import Any
  from typing import Dict
  from typing import List
  from typing import Optional
  import keras_tuner
  import numpy
  from autokeras.engine import tuner
label_desc: Use image node_id 3 for calling the Trie obj's underlying member method code with example usage: obj.nodes() and returns: self