from_response# response successful?success? & successful?# URL not found?missing? & not_found?# redirected?redirect? & redirection?# a server-side error?error? & server_error?
Integration Test
类方法：
app
app=
实例方法：
app
document_root_element
url_options
Request Helpers：
delete
delete_via_redirect
follow_redirect!
get
get_via_redirect
head
patch
patch_via_redirect
post
post_via_redirect
put
put_via_redirect
request_via_redirect
xhr & xml_http_request