code: def verify(self):
      # type: () -> None
      super(TaskTrigger, self).verify()
      if (
          self.metrics or self.variant or self.threshold is not None
      ) and not (
          self.metrics and self.variant and self.threshold is not None
      ):
          raise ValueError("You must provide metric/variant/threshold")
      valid_status = [str(s) for s in Task.TaskStatusEnum]
      if self.on_status and not all(
          s in valid_status for s in self.on_status
      ):
          raise ValueError(
              "Your on_status contains invalid status value: {}".format(
                  self.on_status
              )
          )
      valid_signs = ["min", "minimum", "max", "maximum"]
      if self.value_sign and self.value_sign not in valid_signs:
          raise ValueError(
              "Invalid value_sign `{}`, valid options are: {}".format(
                  self.value_sign, valid_signs
              )
          )
  
imports: import json
  import logging
  from datetime import datetime
  from threading import enumerate
  from typing import List, Optional, Dict, Union, Callable
  from attr import attrs, attrib
  from .job import ClearmlJob
  from .scheduler import BaseScheduleJob, BaseScheduler, ExecutedJob
  from ..task import Task
  from ..backend_api.session.client import APIClient
  from ..backend_interface.util import datetime_to_isoformat, datetime_from_isoformat
label_desc: Use image node_id 2 for calling the TaskTrigger obj's underlying member method code with example usage: obj.verify() without return types