title: Convert [fetchedResultsController fetchedObjects] to NSArray
body: <p>I need to convert my <code>[self.fetchedResultsController fetchedObjects]</code> to <code>NSArray</code>.</p>
  
  <p>I've already tried before use <code>[self.fetchedResultsController fetchedObjects]</code> but it returns me a lot of properties from other Atributes that I don't need. I just want to get a list of values from a concrete attribute called <code>circuito</code> inside the entity <code>Autobus</code>.</p>