class_docstr: A set of tests for the Learner.
class_docstr_tok: ["A","set","of","tests","for","the","Learner","."]
code: def _assign_variables(self, src_learner, dst_learner):
      src_vars = src_learner._agent.collect_policy.variables()
      dst_vars = dst_learner._agent.collect_policy.variables()
      self.assertEqual(len(src_vars), len(dst_vars))
      for src_var, dst_var in zip(src_vars, dst_vars):
          dst_var.assign(src_var)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import functools
  import os
  from absl import logging
  from absl.testing import parameterized
  import numpy
  from six.moves import range
  import tensorflow
  from tf_agents.agents.behavioral_cloning import behavioral_cloning_agent
  from tf_agents.environments import suite_gym
  from tf_agents.environments import tf_py_environment
  from tf_agents.keras_layers import inner_reshape
  from tf_agents.networks import sequential
  from tf_agents.specs import tensor_spec
  from tf_agents.system import system_multiprocessing
  from tf_agents.train import learner
  from tf_agents.train.utils import test_utils
  from tf_agents.train.utils import train_utils
  from tf_agents.trajectories import time_step
  from tf_agents.utils import common
  from tf_agents.utils import test_utils
label_desc: Use image node_id 12 for calling the LearnerTest obj's underlying member method code with example usage: obj._assign_variables(src_learner, dst_learner) without return types