code: public static function sortModelCmp($a, $b)
      {
          if ($a->getCount() == $b->getCount())
              return 0;
          return ($a->getCount() < $b->getCount()) ? 1 : -1;
      }
docs: Sort callback for objects that have getCount()
  @see Sheep_Debug_Model_Model
  
  @param Sheep_Debug_Model_Model|Sheep_Debug_Model_Collection $a
  @param Sheep_Debug_Model_Model|Sheep_Debug_Model_Collection $b
  @return int