class_docstr_tok: []
docstr_tok: []
code: def add_session_callback(self, callback_obj: SessionCallback) -> None:
      """ """
      if isinstance(callback_obj, PeriodicCallback):
          self._group.add_periodic_callback(
              callback_obj.callback,
              callback_obj.period,
              callback_obj.id,
          )
      elif isinstance(callback_obj, TimeoutCallback):
          self._group.add_timeout_callback(
              callback_obj.callback,
              callback_obj.timeout,
              callback_obj.id,
          )
      elif isinstance(callback_obj, NextTickCallback):
          self._group.add_next_tick_callback(
              callback_obj.callback, callback_obj.id
          )
      else:
          raise ValueError(
              f"Expected callback of type PeriodicCallback, TimeoutCallback, NextTickCallback, got: {callback_obj.callback}"
          )
  
imports: from __future__ import annotations
  import logging
  from typing import TYPE_CHECKING, Callable, Sequence
  from ..core.types import ID
  from ..util.tornado import _CallbackGroup
label_desc: Use image node_id 4 for calling the DocumentCallbackGroup obj's underlying member method code with example usage: obj.add_session_callback(callback_obj) without return types