code: def __init__(self, use_cuda):
      super(Stage123Model, self).__init__(
          model_dirname="saved_model",
          stage_name="stage123",
          use_cuda=use_cuda,
      )
  
imports: import numpy
  import parl.layers
  from mlp_model import ActorModel, CriticModel
  from paddle import fluid
  from parl.utils import logger
label_desc: Use image node_id 1 to create a new Stage123Model object from inherited base classes: EnsembleBaseModel with example: obj = Stage123Model(use_cuda)