docstr: update the target network with the training network
  
  Args:
      alpha(float): the decaying factor while updating the target network with the training network.
                  1.0 represents the **assignment**.
docstr_tok: ["update","the","target","network","with","the","training","network","Args",":","alpha","(","float",")",":","the","decaying","factor","while","updating","the","target","network","with","the","training","network",".","1.0","represents","the","*","*","assignment","*","*","."]
code: def sync_target(self, alpha=0):
      """update the target network with the training network
  
      Args:
          alpha(float): the decaying factor while updating the target network with the training network.
                      1.0 represents the **assignment**.
      """
      for param, target_param in zip(
          self.model.parameters(), self.q_target.parameters()
      ):
          target_param.data.copy_(
              alpha * param.data + (1 - alpha) * target_param.data
          )
  
file_path: PARL/parl/algorithms/torch/iql.py
imports: import copy
  import torch
  import torch.nn
  import parl
  import torch.nn.functional
  from parl.utils.utils import check_model_method
label_desc: Use image node_id 4 for calling the IQL obj's underlying member method code with example usage: obj.sync_target(alpha) without return types