code: def test_multistep_scheduler(self):
      net = ToyNet(value=-1)
      engine = Engine(lambda e, b: None)
      ParamSchedulerHandler(
          parameter_setter=net.set_value,
          value_calculator="multistep",
          vc_kwargs={
              "initial_value": 10,
              "gamma": 0.99,
              "milestones": [3, 6],
          },
          epoch_level=True,
          event=Events.EPOCH_COMPLETED,
      ).attach(engine)
      engine.run([0] * 8, max_epochs=10)
      assert_allclose(net.get_value(), 10 * 0.99 * 0.99)
  
file_path: MONAI/tests/test_handler_parameter_scheduler.py
imports: from __future__ import annotations
  import unittest
  from ignite.engine import Engine, Events
  from torch.nn import Module
  from monai.handlers.parameter_scheduler import ParamSchedulerHandler
  from tests.utils import assert_allclose
label_desc: Use image node_id 4 for calling the TestHandlerParameterScheduler obj's underlying member method code with example usage: obj.test_multistep_scheduler() without return types