code: def _all_reduce_sum_fn(distribution, grads_and_vars):
      return distribution.extended.batch_reduce_to(
          ds_reduce_util.ReduceOp.SUM, grads_and_vars
      )
  
file_path: tensorflow-upstream/tensorflow/python/keras/optimizer_v2/utils.py
imports: from tensorflow.python.distribute import central_storage_strategy
  from tensorflow.python.distribute import distribute_lib
  from tensorflow.python.distribute import reduce_util
  from tensorflow.python.ops import clip_ops
  from tensorflow.python.platform import tf_logging
label_desc: Use image node_id 6 for calling a global function with example usage: _all_reduce_sum_fn(distribution, grads_and_vars) and returns: distribution