英语翻译After a new request has been created,any additional opti

any additional optional header fields are added,这是主句:
任何额外的可选标题字段被添加,
After a new request has been created,这是从句,
一个新的请求被已创建后,
as are any header fields specific to the method,这也是从句.
正如:任何具体到这个方法标题字段.