code: def _buildInput(self, num_workers, num_gpus):
      t8 = constant_op.constant(
          [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15],
          types_pb2.DT_FLOAT,
      )
      input_tensors = []
      device_names = []
      for w in range(0, num_workers):
          for d in range(0, num_gpus):
              dn = "/replica:0/task:%d/device:GPU:%d" % (
                  w,
                  d % num_gpus,
              )
              device_names.append(dn)
              with ops.device(dn):
                  input_tensors.append(array_ops.identity(t8))
      return input_tensors, device_names
  
imports: import time
  import numpy
  from tensorflow.core.framework import types_pb2
  from tensorflow.python.distribute.v1 import all_reduce
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor_shape
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import state_ops
  from tensorflow.python.platform import test
  from tensorflow.python.platform import tf_logging
label_desc: Use image node_id 3 for calling the AllReduceTest obj's underlying member method code with example usage: obj._buildInput(num_workers, num_gpus) and returns: input_tensors,  device_names