code: def learn(self):
      (
          total_loss,
          pi_loss,
          vf_loss,
          entropy,
          kl,
      ) = self.fluid_executor.run(
          self.learn_program, fetch_list=self.learn_outputs
      )
      return total_loss, pi_loss, vf_loss, entropy, kl
  
file_path: PARL/benchmark/fluid/IMPALA/atari_agent.py
imports: import numpy
  import paddle.fluid
  import parl
  from parl import layers
  from parl.utils import machine_info
label_desc: Use image node_id 5 for calling the AtariAgent obj's underlying member method code with example usage: obj.learn() and returns: total_loss,  pi_loss,  vf_loss,  entropy,  kl