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: ``True`` if the handler failed to modify the doc
  
          
docstr_tok: ["``","True","``","if","the","handler","failed","to","modify","the","doc"]
code: def failed(self) -> bool:
      """``True`` if the handler failed to modify the doc"""
      return self._failed
  
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 4 for calling the Handler obj's underlying member method code with example usage: obj.failed() and returns: self