code: def save(self, checkpoint):
      if not self.model_built:
          raise RuntimeError(
              "You must call fit_eval or restore first before calling save!"
          )
      state_dict = self.state_dict()
      with open(checkpoint, "wb") as f:
          pickle.dump(state_dict, f)
  
imports: from zoo.orca.automl.model.abstract import BaseModel, ModelBuilder
  import numpy
  from zoo.orca.automl.metrics import Evaluator
  import pickle
  import tensorflow
  from tensorflow.keras import backend
label_desc: Use image node_id 9 for calling the KerasBaseModel obj's underlying member method code with example usage: obj.save(checkpoint) without return types