code: def main(unused_argv):
      keep_running = True
      while keep_running:
          try:
              train(FLAGS.config)
              keep_running = False  # Training completed successfully.
          except tf.errors.UnavailableError as error:
              logging.warning(
                  "UnavailableError encountered during training: %s.",
                  error,
              )
              sys.exit(42)
  
file_path: deepvariant/deepvariant/train.py
imports: import os
  import sys
  import warnings
  from absl import app
  from absl import flags
  from absl import logging
  from clu import metric_writers
  from clu import periodic_actions
  import ml_collections
  from ml_collections.config_flags import config_flags
  import tensorflow
  from deepvariant import data_providers
  from deepvariant import dv_utils
  from deepvariant import keras_modeling
  from official.modeling import optimization
label_desc: Use image node_id 2 for calling a global function with example usage: main(unused_argv) without return types