/**
  * Build a collection of entities from an indexed array of data.
  *
  * @param array       $data
  * @param string|null $entityType
  *
  * @return \Percy\Entity\Collection
  */
 public function buildCollection(array $data, $entityType = null)
 {
     $collection = new Collection();
     foreach ($data as $row) {
         $entity = is_null($entityType) ? $this->getEntityType() : $entityType;
         $entity = new $entity();
         $collection->addEntity($entity->hydrate($row));
     }
     return $collection;
 }