class_docstr: A base class for callback objects associated with Bokeh Documents
  and Sessions.
class_docstr_tok: ["A","base","class","for","callback","objects","associated","with","Bokeh","Documents","and","Sessions","."]
docstr: Args:
     callback (callable) :
  
     id (ID) :
docstr_tok: ["Args",":","callback","(","callable",")",":","id","(","ID",")",":"]
code: def __init__(self, callback: Callback, *, callback_id: ID) -> None:
      """
  
      Args:
         callback (callable) :
  
         id (ID) :
  
      """
      self._id = callback_id
  
      # specify type here until this is released: https://github.com/python/mypy/pull/10548
      self._callback: Callback = 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 1 to create a new SessionCallback object  with example: obj = SessionCallback(callback)