title: ui_metrics in twitter login form
body: <p>I'm doing some apps which require login into a twitter account using HttpWebRequest.
  In the POST request there's a parameter called "ui_metrics", What is this parameter used for? Is there a problem if I didn't send it?
  <a href="https://i.stack.imgur.com/Jk5Xv.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Jk5Xv.jpg" alt="enter image description here"></a></p>
  
  <p>The content of it is generated by this script:
  <a href="https://twitter.com/i/js_inst?c_name=ui_metrics" rel="nofollow noreferrer">https://twitter.com/i/js_inst?c_name=ui_metrics</a></p>
  
  <p>Edit:
  I also want to convert this script to C# or VB.NET, I know how to download it to a string, but how to get the value it returns, which is ui_metrics as shown in the above screen.
  so, To be clear of what I want:</p>
  
  <ol>
  <li>What is this parameter used for?</li>
  <li>Why this javascript is called 3 times? ( I knew this by monitoring web traffic )</li>
  <li>Is there a problem if I didn't send it?</li>
  <li>How to generate the value it returns from the javascript in C# or VB.NET?</li>
  </ol>