I'm using the Microsoft.VisualStudio.Services.Client library (added via NuGet) to connect to my on-prem Azure Dev Ops server and query various bits of information regarding pull requests. I'd like to make a little notification application that can alert me if someone has replied to a comment I made on a pull request. The trick is that I only want to see the notification if I haven't already looked at it.
I know that the system knows when I last looked at the pull request because it decorates pull requests with new content (comments, new code, etc.) with a little dot and when I open a pull request, it tells me that there are new comments since I visited last and tells me how long ago I looked at it.
How do I get access to the date that I opened the pull request in the web via the client libraries or REST? In other words, how would my app know that I have or haven't looked at new comments via the web page?