def create_trigger_driver(windowing, is_batch=False, phased_combine_fn=None):

  # TODO(robertwb): We can do more if we know elements are in timestamp
  # sorted order.
  if windowing.is_default() and is_batch:
    driver = DefaultGlobalBatchTriggerDriver()
  else:
    driver = GeneralTriggerDriver(windowing)

  if phased_combine_fn:
    # TODO(ccy): Refactor GeneralTriggerDriver to combine values eagerly using
    # the known phased_combine_fn here.
    driver = CombiningTriggerDriver(phased_combine_fn, driver)
  return driver
Returns dict of vbucket_id->[msgs] grouped by msg's vbucket_id.
dataset/ETHPy150Open GoogleCloudPlatform/DataflowPythonSDK/google/cloud/dataflow/transforms/trigger.py/create_trigger_driver--crossover with--dataset/ETHPy150Open membase/membase-cli/pump.py/Batch.group_by_vbucket_id