/**
  * Indexes several content objects.
  *
  * Notes:
  * - Does not force a commit on solr, depends on solr config, use {@see commit()} if you need that.
  * - On large amounts of data make sure to iterate with several calls to this function with a limited
  *   set of content objects, amount you have memory for depends on server, size of objects, & PHP version.
  *
  * @todo: This method, {@see purgeIndex}, & {@see commit()} is needed for being able to bulk index content.
  *       However it is not added to an official SPI interface yet as we anticipate adding a bulkIndexDocument
  *       using eZ\Publish\SPI\Search\Document instead of bulkIndexContent based on Content objects. However
  *       that won't be added until we have several stable or close to stable advance search engines to make
  *       sure we match the features of these. 
  *       See also {@see Solr\Content\Search\Gateway\Native::bulkIndexContent} for further Solr specific info.
  *
  * @param \eZ\Publish\SPI\Persistence\Content[] $contentObjects
  */
 public function bulkIndexContent(array $contentObjects)
 {
     $documents = array();
     foreach ($contentObjects as $content) {
         $documents[] = $this->mapper->mapContentBlock($content);
     }
     if (!empty($documents)) {
         $this->gateway->bulkIndexDocuments($documents);
     }
 }
 /**
  * Generate search document for Content object to be indexed by a search engine.
  *
  * @param \eZ\Publish\SPI\Persistence\Content $content
  * @return \eZ\Publish\SPI\Search\Document
  */
 public function generateDocument(Content $content)
 {
     return $this->mapper->mapContentBlock($content);
 }