@gen.engine
  def _RepairMultipleShareNew(self, activity, callback):
    assert activity.name == 'share_new', activity
    act_args = json.loads(activity.json)
    del act_args['follower_ids']

    # Update share_new => share_existing.
    update_activity = Activity.CreateFromKeywords(viewpoint_id=activity.viewpoint_id,
                                                  activity_id=activity.activity_id,
                                                  name='share_existing',
                                                  json=json.dumps(act_args))
    yield gen.Task(update_activity.Update, self._client)
    logging.warning('  updated activity: %s', activity.activity_id)

    callback()
Replaces extraneous share_new activities with corresponding
dataset/ETHPy150Open viewfinderco/viewfinder/backend/db/tools/dbchk.py/DatabaseChecker._RepairMultipleShareNew