docstr: Use the policy model of self.model to predict means and logvars of actions
          
docstr_tok: ["Use","the","policy","model","of","self.model","to","predict","means","and","logvars","of","actions"]
code: def predict(self, obs):
      """Use the policy model of self.model to predict means and logvars of actions"""
      means, logvars = self.model.policy(obs)
      return means
  
file_path: PARL/parl/algorithms/fluid/ppo.py
imports: import warnings
  import numpy
  from copy import deepcopy
  from paddle import fluid
  from parl.core.fluid import layers
  from parl.core.fluid.algorithm import Algorithm
label_desc: Use image node_id 4 for calling the PPO obj's underlying member method code with example usage: obj.predict(obs) and returns: means