code: def handler_mod(task: dict, rolling_gen):
      """
      Help to modify the handler end time when using RollingGen
      It try to handle the following case
  
      - Hander's data end_time is earlier than  dataset's test_data's segments.
  
          - To handle this, handler's data's end_time is extended.
  
      If the handler's end_time is None, then it is not necessary to change it's end time.
  
      Args:
          task (dict): a task template
          rg (RollingGen): an instance of RollingGen
      """
      try:
          interval = rolling_gen.ta.cal_interval(
              task["dataset"]["kwargs"]["handler"]["kwargs"][
                  "end_time"
              ],
              task["dataset"]["kwargs"]["segments"][
                  rolling_gen.test_key
              ][1],
          )
          # if end_time < the end of test_segments, then change end_time to allow load more data
          if interval < 0:
              task["dataset"]["kwargs"]["handler"]["kwargs"][
                  "end_time"
              ] = copy.deepcopy(
                  task["dataset"]["kwargs"]["segments"][
                      rolling_gen.test_key
                  ][1]
              )
      except KeyError:
          # Maybe dataset do not have handler, then do nothing.
          pass
      except TypeError:
          # May be the handler is a string. `"handler.pkl"["kwargs"]` will raise TypeError
          # e.g. a dumped file like file:///<file>/
          pass
  
imports: import abc
  import copy
  import pandas
  from typing import Dict, List, Union, Callable
  from qlib.utils import transform_end_date
  from .utils import TimeAdjuster
label_desc: Use image node_id 2 for calling a global function with example usage: handler_mod(task, rolling_gen) without return types