PerfURLConnectionWithDelegateClassInit https://blog.mozilla.org/security/files/2015/05/HTTPS-FAQ.pdf PerfURLConnectionWithDelegate https://blog.mozilla.org/security/files/2015/05/HTTPS-FAQ.pdf PerfURLConnectionWithDelegateStartImmediately https://blog.mozilla.org/security/files/2015/05/HTTPS-FAQ.pdf PerfURLConnectionAsyncRequest https://blog.mozilla.org/security/files/2015/05/HTTPS-FAQ.pdf PerfURLSessionDownloadTaskWithDelegate https://blog.mozilla.org/security/files/2015/05/HTTPS-FAQ.pdf PerfURLSessionDataTaskWithDelegate https://blog.mozilla.org/security/files/2015/05/HTTPS-FAQ.pdf PerfURLSessionDownloadTask https://blog.mozilla.org/security/files/2015/05/HTTPS-FAQ.pdf PerfURLSessionDataTask https://blog.mozilla.org/security/files/2015/05/HTTPS-FAQ.pdf