code: def _get_indexed_slices(
      self, devices, start_i, variable_length, as_per_replica=True
  ):
      dense_shape = [10, 2]
      values = (
          [[1.0, 2.0]],
          [[3.0, 4.0]],
          [[2.0, 1.0]],
          [[0.0, 0.0]],
          [[3.0, 1.0]],
          [[2.0, 1.0]],
      )
      indices = ([1], [2], [3], [4], [5], [6])
  
      # values and indices that have variable lengths.
      vl_values = (
          [[1.0, 2.0], [3.0, 4.0]],
          [[3.0, 4.0]],
          [[2.0, 1.0]],
          [[0.0, 0.0]],
          [[3.0, 1.0], [2.0, 1.0]],
          [[2.0, 1.0]],
      )
      vl_indices = ([1, 2], [2], [3], [4], [5, 6], [6])
  
      indexed_slices = []
      for i, d in enumerate(devices):
          idx = i + start_i
          indexed_slices.append(
              _make_indexed_slices(
                  vl_values[idx] if variable_length else values[idx],
                  vl_indices[idx] if variable_length else indices[idx],
                  dense_shape,
                  d,
              )
          )
      if as_per_replica:
          per_replica = value_lib.PerReplica(indexed_slices)
          return per_replica
      else:
          return indexed_slices
  
imports: import itertools
  import os
  import threading
  import time
  from absl.testing import parameterized
  import numpy
  from tensorflow.core.protobuf import config_pb2
  from tensorflow.python.distribute import cluster_resolver
  from tensorflow.python.distribute import collective_all_reduce_strategy
  from tensorflow.python.distribute import collective_util
  from tensorflow.python.distribute import combinations
  from tensorflow.python.distribute import cross_device_ops
  from tensorflow.python.distribute import cross_device_utils
  from tensorflow.python.distribute import device_util
  from tensorflow.python.distribute import distribute_utils
  from tensorflow.python.distribute import multi_worker_test_base
  from tensorflow.python.distribute import multi_worker_util
  from tensorflow.python.distribute import reduce_util
  from tensorflow.python.distribute import strategy_combinations
  from tensorflow.python.distribute import values
  from tensorflow.python.eager import context
  from tensorflow.python.eager import test
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import indexed_slices
  from tensorflow.python.framework import kernels
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import collective_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import variables
label_desc: Use image node_id 6 for calling the CollectiveAllReduceTest obj's underlying member method code with example usage: obj._get_indexed_slices(devices, start_i, variable_length, as_per_replica) and returns: per_replica, indexed_slices