title: ag-grid: "How to scroll to last known position"?
body: <p>Ag-Grid offers the method <code>ensureIndexVisible(index, 'middle');</code> With that method it is easy to scroll to an choosen index. But how do I get the last known index of the scrolling position from the user?</p>
  
  <p>An example:
  We have a table with 600 rows.
  The user is scrolling around - an update happens. The table changed a bit.
  Now I have the behaviour that the table is scrolling to the top. The user has now to scroll again to his last position. </p>
  
  <p>I would like to redirect the user to hist last scrolling position: <code>ensureIndexVidisble(USERS_LAST_KNOWN_SCROLLING_POSITION, 'middle');</code></p>
  
  <p>In addition to information: the user does not work in the table. So I cannot save his last click on a row.</p>
  
  <p>How can I achieve this?</p>