title: Best way to update a single element using Paging Library
body: <p>Which is the best way to update a single element when using the new paging library?</p>
  
  <p>Let's say we have the <a href="https://github.com/googlesamples/android-architecture-components/tree/master/PagingWithNetworkSample" rel="noreferrer">Paging with network</a> google sample using the <code>PageKeyedSubredditDataSource</code>. Imagine we want to make a change of a single element of <code>RedditPost</code>. So, we want to check if it is in the list and if so, update it. The update should not be as easy as calling invalidate() which will make a call to the first page (maybe the RedditPost is in the 5th page. We don't want to update all elements, just one).</p>