code: def post_handler_err(self, function_arn, invocation_id, handler_err):
          
          url = self._get_work_url(function_arn)
  
          runtime_logger.info('Posting handler error for invocation id [{}] to {}'.format(invocation_id, url))
  
          payload = json.dumps({
              "errorMessage": handler_err,
          }).encode('utf-8')
  
          request = Request(url, payload)
          request.add_header(HEADER_INVOCATION_ID, invocation_id)
          request.add_header(HEADER_FUNCTION_ERR_TYPE, "Handled")
          request.add_header(HEADER_AUTH_TOKEN, self.auth_token)
  
          urlopen(request)
  
          runtime_logger.info('Posted handler error for invocation id [{}]'.format(invocation_id))
docs: Post the error message from executing the function handler for :code:`function_arn`
          with specifid :code:`invocation_id`
  
  
          :param function_arn: Arn of the Lambda function which has the handler error message.
          :type function_arn: string
  
          :param invocation_id: Invocation ID of the work that is being requested
          :type invocation_id: string
  
          :param handler_err: the error message caught from handler
          :type handler_err: string