title: What is the default HTTP user agent string for NSURLConnection and NSURLSession on macOS?
body: <p><a href="https://stackoverflow.com/q/36379347/9636">does NSURLSession send user-agent automatically</a> has <a href="https://stackoverflow.com/a/36380210/9636">an answer</a> that describes the <code>NSURLSession</code> default HTTP <code>User-Agent</code> string for iOS. I want to know the default format for <code>macOS</code> (preferably with supporting documentation), and the default format for <code>NSURLConnection</code> as well.</p>
  
  <p>I'm seeing some very old <code>User-Agent</code> strings on my site, and I'm trying to verify potential sources.</p>