code: def update_target_param():
      vars = tf.global_variables()
      vars_mapping = {x.name: x for x in vars}
      ops = []
      for v in vars:
          target_name = v.name
          if target_name.startswith("target"):
              new_name = target_name.replace("target/", "")
              logger.info(
                  "Target Network Update: {} <- {}".format(
                      target_name, new_name
                  )
              )
              ops.append(v.assign(vars_mapping[new_name]))
      return tf.group(*ops, name="update_target_network")
  
file_path: tensorpack/examples/DeepQNetwork/DQNModel.py
imports: import abc
  from tensorpack import ModelDesc
  from tensorpack.compat import tfv1
  from tensorpack.tfutils import gradproc, optimizer, summary, varreplace
  from tensorpack.tfutils.scope_utils import auto_reuse_variable_scope
  from tensorpack.utils import logger
label_desc: Use image node_id 7 for calling the Model obj's underlying member method code with example usage: obj.update_target_param() and returns: tf