class_docstr: Tests for ops in horovod.tensorflow.keras using multiple process sets.
class_docstr_tok: ["Tests","for","ops","in","horovod.tensorflow.keras","using","multiple","process","sets","."]
docstr: Prevent that one process shuts down Horovod too early
docstr_tok: ["Prevent","that","one","process","shuts","down","Horovod","too","early"]
code: def tearDown(self):
      """Prevent that one process shuts down Horovod too early"""
      with tf.device("/cpu:0"):
          b = hvd.allreduce(
              tf.constant([0.0]), name="global_barrier_after_test"
          )
          _ = self.evaluate(b)
  
file_path: horovod/test/parallel/test_tensorflow2_keras_process_sets.py
imports: import tensorflow
  import warnings
  from packaging import version
  import pytest
  from tensorflow import keras
  import horovod.tensorflow.keras
  from horovod.runner.common.util.env import get_env_rank_and_size
label_desc: Use image node_id 3 for calling the Tf2KerasProcessSetsTests obj's underlying member method code with example usage: obj.tearDown() without return types