docstr: use value model self.model to predict the action value
          
docstr_tok: ["use","value","model","self.model","to","predict","the","action","value"]
code: def predict(self, obs):
      """use value model self.model to predict the action value"""
      pred_q = self.model(obs)
      return pred_q
  
file_path: PARL/parl/algorithms/torch/ddqn.py
imports: import warnings
  import copy
  import torch
  import torch.optim
  import torch.nn.functional
  import parl
  from parl.utils.utils import check_model_method
  import numpy
label_desc: Use image node_id 2 for calling the DDQN obj's underlying member method code with example usage: obj.predict(obs) and returns: pred_q