def render(self, template_name: str, **ctx):
        """
        Convenience method for rendering a template.

        :param template_name: The template's name. Can either be a full path,
                              or a filename in the controller's template folder.
        :param ctx: Context variables to pass into the template.
        """
        if '.' not in template_name:
            template_file_extension = (self.Meta.template_file_extension
                                       or app.config.TEMPLATE_FILE_EXTENSION)
            template_name = f'{template_name}{template_file_extension}'
        if self.Meta.template_folder_name and os.sep not in template_name:
            template_name = os.path.join(self.Meta.template_folder_name,
                                         template_name)
        return render_template(template_name, **ctx)
Convenience method for rendering a template.

        :param template_name: The template's name. Can either be a full path,
                              or a filename in the controller's template folder.
        :param ctx: Context variables to pass into the template.