code: def add_error_processor(self, func, cls=None):
          # type: (Callable, Optional[type]) -> None
          Register a scope local error processor on the scope.
  
          The error processor works similar to an event processor but is
          invoked with the original exception info triple as second argument.
          """
          if cls is not None:
              real_func = func
  
              def func(event, exc_info):
                  try:
                      is_inst = isinstance(exc_info[1], cls)
                  except Exception:
                      is_inst = False
                  if is_inst:
                      return real_func(event, exc_info)
                  return event
  
          self._error_processors.append(func)
docs: Register a scope local error processor on the scope.
  
          The error processor works similar to an event processor but is
          invoked with the original exception info triple as second argument.