title: Laravel pluck an array from nested relationship
body: <p>I need to get only the <code>roomnumber</code> arrays returned from the following query:</p>
  
  <pre><code>$roomnumbers = Room::with(['floorroomcount' =&gt; function($query){
                  $query-&gt;with('roomnumber')-&gt;get();
          }])-&gt;where('roomtype_id', $roomtype_id)-&gt;get();
  </code></pre>
  
  <p>Tried:
  The follow pluck is returning <code>floorroomcount</code></p>
  
  <pre><code>$roomnumbers-&gt;pluck('floorroomcount');
  </code></pre>
  
  <p>but i need <code>roomnumber</code> array, how can i get?</p>