code: def flush(self):
      self._sess._hooks[1]._summary_writer.flush()
  
file_path: tensor2tensor/tensor2tensor/utils/metrics_hook_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import contextlib
  import os
  import shutil
  from tensor2tensor.utils import metrics_hook
  import tensorflow.compat.v1
label_desc: Use image node_id 4 for calling the MetricsHookTest obj's underlying member method code with example usage: obj.flush() without return types