docstr: use actor model of self.policy to predict the action
          
docstr_tok: ["use","actor","model","of","self.policy","to","predict","the","action"]
code: def predict(self, obs):
      """use actor model of self.policy to predict the action"""
      mean, _ = self.actor.policy(obs)
      mean = layers.tanh(mean) * self.max_action
      return mean
  
file_path: PARL/parl/algorithms/fluid/sac.py
imports: from parl.core.fluid import layers
  from copy import deepcopy
  import numpy
  from paddle import fluid
  from paddle.fluid.layers import Normal
  from parl.core.fluid.algorithm import Algorithm
label_desc: Use image node_id 2 for calling the SAC obj's underlying member method code with example usage: obj.predict(obs) and returns: mean