code: def _op_dependencies(op):
      """Returns the data and control dependencies of a tf.Operation combined."""
      deps = []
      for node in itertools.chain(op.inputs, op.control_inputs):
          if isinstance(node, tensor.Tensor):
              node = node.op
          assert isinstance(node, ops.Operation)
          deps.append(node)
      return deps
  
imports: import collections
  import dataclasses
  import functools
  import io
  import itertools
  import threading
  from absl import app
  from tensorflow.python.compat import v2_compat
  from tensorflow.python.distribute import collective_all_reduce_strategy
  from tensorflow.python.distribute import multi_process_runner
  from tensorflow.python.distribute import multi_worker_test_base
  from tensorflow.python.distribute import tpu_strategy
  from tensorflow.python.distribute import values
  from tensorflow.python.eager import context
  from tensorflow.python.framework import config
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import array_ops_stack
  from tensorflow.python.util import nest
label_desc: Use image node_id 7 for calling a global function with example usage: _op_dependencies(op) and returns: deps