code: def _build_easy_ensemble(self, subnetworks):
      return self.easy_ensembler.build_ensemble(
          subnetworks=subnetworks,
          previous_ensemble_subnetworks=None,
          features=None,
          labels=None,
          logits_dimension=None,
          training=None,
          iteration_step=None,
          summary=self.summary,
          previous_ensemble=None,
          previous_iteration_checkpoint=None,
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
  import contextlib
  from absl.testing import parameterized
  from adanet import ensemble
  from adanet import subnetwork
  from adanet import tf_compat
  from adanet.core.summary import Summary
  import mock
  import tensorflow.compat.v2
  from tensorflow.python.eager import context
  from tensorflow.python.framework import test_util
label_desc: Use image node_id 2 for calling the ComplexityRegularizedEnsemblerTest obj's underlying member method code with example usage: obj._build_easy_ensemble(subnetworks) and returns: self