code: def _set_trainable_variables(var_list):
      _clear_trainable_variables()
      for var in var_list:
          assert isinstance(var, tf.Variable)
          tf_compat.v1.add_to_collections(
              tf_compat.v1.GraphKeys.TRAINABLE_VARIABLES, var
          )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
  import contextlib
  import copy
  import functools
  import inspect
  import os
  from absl import logging
  from adanet import ensemble
  from adanet import subnetwork
  from adanet import tf_compat
  from adanet.core.architecture import _Architecture
  from adanet.core.eval_metrics import _EnsembleMetrics
  from adanet.core.eval_metrics import _SubnetworkMetrics
  from adanet.core.summary import monkey_patched_summaries
  import tensorflow.compat.v1
  import tensorflow.compat.v2
label_desc: Use image node_id 6 for calling a global function with example usage: _set_trainable_variables(var_list) without return types