class_docstr: Warm starts current trial with uniform average of previous trials.
class_docstr_tok: ["Warm","starts","current","trial","with","uniform","average","of","previous","trials","."]
code: def _combine_previous_trial_variables(self, trial_to_var):
      _, variables = list(zip(*trial_to_var))
      return tf.reduce_mean(
          input_tensor=tf.stack(variables, axis=0), axis=0
      )
  
file_path: model_search/model_search/meta/transfer_learning.py
imports: import abc
  from absl import logging
  from model_search.architecture import architecture_utils
  import tensorflow.compat.v2
label_desc: Use image node_id 2 for calling the UniformAverageTransferLearningHook obj's underlying member method code with example usage: obj._combine_previous_trial_variables(trial_to_var) and returns: tf