code: def add_exception_handler(self, exception_handler):
          # type: (AbstractExceptionHandler) -> None
          
          if exception_handler is None or not isinstance(
                  exception_handler, AbstractExceptionHandler):
              raise DispatchException(
                  "Input is not an AbstractExceptionHandler instance")
          self._exception_handlers.append(exception_handler)
docs: Checks the type before adding it to the exception_handlers
          instance variable.
  
          :param exception_handler: Exception Handler instance.
          :type exception_handler: ask_sdk_runtime.dispatch_components.exception_components.AbstractExceptionHandler
          :raises: :py:class:`ask_sdk_runtime.exceptions.DispatchException` if a
              null input is provided or if the input is of invalid type