class_docstr: Delays the start of the current worker process until global step
  K * task_id is reached. K is a parameter.
code: def __init__(self, params, model_dir, run_config):
      TrainingHook.__init__(self, params, model_dir, run_config)
      self._task_id = self._run_config.task_id
      self._delay_k = self.params["delay_k"]
      self._wait_until_step = int(self._delay_k * self._task_id)
      tf.train.GlobalStepWaiterHook.__init__(
          self, self._wait_until_step
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  import abc
  import os
  import numpy
  import six
  import yaml
  import tensorflow
  from tensorflow.python.training.basic_session_run_hooks import SecondOrStepTimer
  from tensorflow.python.training import session_manager
  from tensorflow.python.client import timeline
  from tensorflow import gfile
  from seq2seq.configurable import Configurable, abstractstaticmethod
  from seq2seq import graph_utils, global_vars
label_desc: Use image node_id 1 to create a new DelayStartHook object from inherited base classes: TrainingHook, tf.train with example: obj = DelayStartHook(params, model_dir, run_config)