title: YouTube API ListResponse ETag inconsistency
body: <p>Responses to an identical <code>commentThread</code> list requests where another page of results exist return different <code>etag</code> values for the <code>commentThreadListResponse</code>.</p>
  
  <p>When the requests are made and all items are returned in the first page of results, (i.e. no <code>nextPageToken</code> is supplied with the response), the responses' <code>etag</code> values are unchanged (and hence useful).</p>
  
  <p>The result of this is that caching of list requests (often the most costly) is useless unless the entire list result set is returned in one page - even if the result set is identical.</p>
  
  <p>Is anyone aware that this is a bug or expected performance? Does anyone know a route to make etags useful for list requests?</p>
  
  <p>It seems to me that it's likely the <code>etag</code> generation for the list response includes the <code>nextPageToken</code> in it's hashing strategy, as the <code>nextPageToken</code> is different for each response.</p>