class_docstr: Provide a mechanism for Bokeh applications to build up new Bokeh
  Documents.
class_docstr_tok: ["Provide","a","mechanism","for","Bokeh","applications","to","build","up","new","Bokeh","Documents","."]
docstr: If the handler fails, may contain a traceback or other details.
  
          
docstr_tok: ["If","the","handler","fails",",","may","contain","a","traceback","or","other","details","."]
code: def error_detail(self) -> str | None:
      """If the handler fails, may contain a traceback or other details."""
      return self._error_detail
  
imports: from __future__ import annotations
  import logging
  import os
  import sys
  import traceback
  from typing import TYPE_CHECKING, Any
  from ...document import Document
  from ..application import ServerContext, SessionContext
label_desc: Use image node_id 3 for calling the Handler obj's underlying member method code with example usage: obj.error_detail() and returns: self