def update_target_params(self, net):
        '''
            updates kept parameters to that of another model
            Args:
                net: another PPO_Model instance
        '''
        self.actor.load_state_dict(net.actor.state_dict())
        self.critic.load_state_dict(net.critic.state_dict())

        if self.rnn_config.if_rnn_policy:
            self.rnn_stem.load_state_dict(net.rnn_stem.state_dict())

        if self.if_pixel_input:
            self.cnn_stem.load_state_dict(net.cnn_stem.state_dict())

        if self.use_z_filter:
            self.z_filter.load_state_dict(net.z_filter.state_dict())

            updates kept parameters to that of another model
            Args:
                net: another PPO_Model instance
        
surreal/model/ppo_net.py