refs vufind-org#2999 remove function setResultSetIdentifier in Abstra…

…ctBackend - set uuid only ON record or collection"

This also reverts commit 48e5a10.

module/VuFindSearch/src/VuFindSearch/Backend/AbstractBackend.php

@@ -56,13 +56,6 @@ abstract class AbstractBackend implements BackendInterface, LoggerAwareInterface
      */
     protected $collectionFactory = null;
 
-    /**
-     * Record collection.
-     *
-     * @var RecordCollectionInterface|null
-     */
-    protected $recordCollection = null;
-
     /**
      * Backend identifier.
      *
@@ -131,18 +124,6 @@ protected function injectSourceIdentifier(RecordCollectionInterface $response)
         return $response;
     }
 
-    /**
-     * Sets the result set identifier for the record collection.
-     *
-     * @param string $uuid A valid UUID associated with the data set.
-     *
-     * @return void
-     */
-    public function setResultSetIdentifier(string $uuid)
-    {
-        $this->recordCollection->setResultSetIdentifier($uuid);
-    }
-
     /**
      * Generates a shorter UUID-like identifier.
      *