code: def add_exception_handler(self, exception_handler):
          # type: (AbstractExceptionHandler) -> None
          
          if exception_handler is None:
              raise RuntimeConfigException(
                  "Valid Exception Handler instance to be provided")
  
          if not isinstance(exception_handler, AbstractExceptionHandler):
              raise RuntimeConfigException(
                  "Input should be an ExceptionHandler instance")
  
          self.exception_handlers.append(exception_handler)
docs: Register input to the exception handlers list.
  
          :param exception_handler: Exception Handler instance to be
              registered.
          :type exception_handler: AbstractExceptionHandler
          :return: None