code: def _update_application_request(app_metadata, application_id):
      
      request = {
          'ApplicationId': application_id,
          'Author': app_metadata.author,
          'Description': app_metadata.description,
          'HomePageUrl': app_metadata.home_page_url,
          'Labels': app_metadata.labels,
          'ReadmeUrl': app_metadata.readme_url
      }
      return {k: v for k, v in request.items() if v}
docs: Construct the request body to update application.
  
      :param app_metadata: Object containing app metadata
      :type app_metadata: ApplicationMetadata
      :param application_id: The Amazon Resource Name (ARN) of the application
      :type application_id: str
      :return: SAR UpdateApplication request body
      :rtype: dict