title: AG Grid change detection for the whole grid
body: <p>The team is working with Angular AG-Grid. The grid itself has 52 columns with up to 40,000 rows.</p>
  <p>We are supposed to create some kind of change detection so that the user will be notified about having unsaved changes (by that I mean - didn't hit the 'Save to the database' button) when trying to hit F5/refresh button or closing the app completely.
  I couldn't find anything in the AG-Grid documentation that would allow us to compare initial state of the grid when the data was first loaded to the changes that the user made.
  We are using @HostListener elsewhere for the 'window:beforeunload' event but that is the next step. First, I'd like to find out how to handle change detection in such a big grid.</p>