title: cellForRowAtIndexPath: being called immediately while numberOfRowsInSection: is not called
body: <p>I've encountered this issue a few times after the <code>reloadData</code> method on a <strong>UITableView</strong> is invoked, and I haven't figured out why?</p>
  
  <p>This is a problem because if the data of table view is updated, the <code>tableview</code> will unnecessarily query the cell on a non-existent row. It is non-existent, because the <code>numberOfRowsInSection:</code> somehow is not called before this is happening. </p>
  
  <p>Is it affected by how the <code>reloadData</code> method is being <em>invoked</em>? (It is invoked on the main thread, not anywhere else).</p>
  
  <p><strong>Update:</strong></p>
  
  <p><code>cellForRowAtIndexPath:</code> could be invoked by other means such as querying <code>visibleCells</code>.
  It may be the case that this isn't part of <code>reloadData</code>.</p>