class_docstr: Callback for logging hyperparameters to TensorBoard.
  
  NOTE: This callback only works in TensorFlow eager mode.
code: def on_train_end(self, logs=None):
      del logs  # unused
      with self._get_writer().as_default():
          pb = summary.session_end_pb(api_pb2.STATUS_SUCCESS)
          raw_pb = pb.SerializeToString()
          tf.compat.v2.summary.experimental.write_raw_pb(raw_pb, step=0)
      self._writer = None
  
file_path: tensorboard/tensorboard/plugins/hparams/_keras.py
imports: import tensorflow
  from tensorboard.plugins.hparams import api_pb2
  from tensorboard.plugins.hparams import summary
  from tensorboard.plugins.hparams import summary_v2
label_desc: Use image node_id 4 for calling the Callback obj's underlying member method code with example usage: obj.on_train_end(logs) without return types