code: def generate(self, task: dict):
      res = []
      for hr in self.horizon:
          # Add horizon
          t = copy.deepcopy(task)
          self.set_horizon(t, hr)
  
          # adjust segment
          segments = self.ta.align_seg(
              t["dataset"]["kwargs"]["segments"]
          )
          trunc_segments(
              self.ta,
              segments,
              days=hr + self.label_leak_n,
              test_key=self.test_key,
          )
          t["dataset"]["kwargs"]["segments"] = segments
          res.append(t)
      return res
  
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 3 for calling the MultiHorizonGenBase obj's underlying member method code with example usage: obj.generate(task) and returns: res