下列代码中，使用了requests的Session对象，并调用prepare_request()为使prepped为赋值。有关Prepped这个对象的作用，下列描述最为符合的是（ ）。 from requests import Request, Session s = Session() req = Request('GET', url, data=data, headers=headers) prepped = s.prepare_request(req) # do something with prepped.body prepped.body = 'Seriously, send exactly these bytes.' # do something with prepped.headers prepped.headers['Keep-Dead'] = 'parrot' resp = s.send(prepped, stream=stream, verify=verify, proxies=proxies, cert=cert, timeout=timeout ) print(resp.status_code)