code: public function init(Varien_Data_Collection_Db $collection)
      {
          $this->class = get_class($collection);
          $this->type = $collection instanceof Mage_Eav_Model_Entity_Collection_Abstract ? self::TYPE_EAV : self::TYPE_FLAT;
          $this->query = $collection->getSelectSql(true);
          $this->count = 0;
      }
docs: Captures information from specified collection
  
  @param Varien_Data_Collection_Db $collection