diff --git a/.github/workflows/phpunit-integration.yml b/.github/workflows/phpunit-integration.yml
new file mode 100644
index 0000000..08b2bb8
--- /dev/null
+++ b/.github/workflows/phpunit-integration.yml
@@ -0,0 +1,127 @@
+name: PHPUnit-Integration
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+      - stable*
+
+env:
+  APP_NAME: workflow_ocr
+  NEXTCLOUD_PORT: 8080
+  NEXTCLOUD_USER: "admin"
+  NEXTCLOUD_PASS: "password"
+  NC_HAPROXY_PASSWORD: "some_secure_password"
+  NC_HAPROXY_PORT: 2375
+  DB_PORT: 4444
+  MYSQL_ROOT_PASSWORD: "rootpassword"
+
+jobs:
+  # Do not change this name, it is used in the integration tests
+  github-php-integrationtests:
+    runs-on: ubuntu-24.04
+    services:
+      docker-socket-proxy:
+        image: ghcr.io/nextcloud/nextcloud-appapi-dsp:release
+        env:
+          NC_HAPROXY_PASSWORD: "some_secure_password"
+        options: --privileged 
+        volumes:
+          - /var/run/docker.sock:/var/run/docker.sock
+        ports:
+          - 2375:2375
+      mysql:
+        image: mariadb:10.5
+        ports:
+          - 4444:3306/tcp
+        env:
+          MYSQL_ROOT_PASSWORD: rootpassword
+        options: --health-cmd="mysqladmin ping" --health-interval 5s --health-timeout 2s --health-retries 5
+    
+    strategy:
+      fail-fast: false
+      matrix:
+        php-versions: ['8.3']
+        databases: ['mysql']
+        server-versions: ['stable31']
+
+    name: php-integrationtests${{ matrix.php-versions }}-${{ matrix.databases }}
+
+    steps:
+      - name: Checkout server
+        uses: actions/checkout@v4
+        with:
+          repository: nextcloud/server
+          ref: ${{ matrix.server-versions }}
+
+      - name: Checkout submodules
+        shell: bash
+        run: |
+          auth_header="$(git config --local --get http.https://github.com/.extraheader)"
+          git submodule sync --recursive
+          git -c "http.extraheader=$auth_header" -c protocol.version=2 submodule update --init --force --recursive --depth=1
+
+      - name: Checkout app
+        uses: actions/checkout@v4
+        with:
+          path: apps/${{ env.APP_NAME }}
+
+      - name: Set up php ${{ matrix.php-versions }}
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-versions }}
+          tools: phpunit
+          extensions: mbstring, iconv, fileinfo, intl, sqlite, pdo_sqlite, gd, zip, imagick
+          coverage: none
+
+      - name: Install composer dependencies
+        working-directory: apps/${{ env.APP_NAME }}
+        run: composer i
+
+      # Note: ./occ maintenance:mimetype:update-db is required to avoid
+      # issues with the application/pdf mimetype
+      - name: Set up Nextcloud
+        run: |
+          mkdir data
+          ./occ maintenance:install --verbose --database=${{ matrix.databases }} --database-name=nextcloud \
+            --database-host=127.0.0.1 --database-port=${{ env.DB_PORT }} --database-user=root --database-pass=${{ env.MYSQL_ROOT_PASSWORD }} \
+            --admin-user ${{ env.NEXTCLOUD_USER }} --admin-pass ${{ env.NEXTCLOUD_PASS }}
+          ./occ app:enable ${{ env.APP_NAME }}
+          ./occ maintenance:mimetype:update-db
+          php -S localhost:${{ env.NEXTCLOUD_PORT }} &
+
+      - name: Checkout AppApi
+        uses: actions/checkout@v4
+        with:
+          repository: nextcloud/app_api
+          ref: ${{ matrix.server-versions }}
+          path: apps/app_api
+
+      - name: Set up AppApi/ExApp infrastructure
+        run: |
+          ./occ app:enable app_api
+          ./occ app_api:daemon:register local_docker "docker-socket-proxy" \
+            "docker-install" "http" "localhost:${{ env.NC_HAPROXY_PORT }}" "http://localhost:${{ env.NEXTCLOUD_PORT }}" \
+            --set-default --haproxy_password="${{ env.NC_HAPROXY_PASSWORD }}"
+          ./occ app_api:app:register workflow_ocr_backend \
+            --wait-finish \
+            --info-xml https://raw.githubusercontent.com/R0Wi-DEV/workflow_ocr_backend/refs/heads/${{ matrix.server-versions }}/appinfo/info.xml
+
+      - name: PHPUnit
+        working-directory: apps/${{ env.APP_NAME }}
+        run: make php-integrationtest
+
+      - name: Write OCR Backend logs to file
+        if: failure()
+        run: |
+          docker logs nc_app_workflow_ocr_backend > data/ocr_backend.log
+
+      - name: Upload logs
+        if: failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: logs
+          path: data/*.log
+
+
diff --git a/lib/Service/OcrService.php b/lib/Service/OcrService.php
index daf2b40..b126c69 100644
--- a/lib/Service/OcrService.php
+++ b/lib/Service/OcrService.php
@@ -138,7 +138,15 @@ public function runOcrProcess(int $fileId, string $uid, WorkflowSettings $settin
 			$this->initUserEnvironment($uid);
 
 			$file = $this->getNode($fileId);
-			
+
+			$this->logger->debug('Begin processing file', [
+				'fileId' => $fileId,
+				'file' => $file,
+				'path' => $file->getPath(),
+				'permissions' => $file->getPermissions(),
+				'mimeType' => $file->getMimeType()
+			]);
+
 			$fileMtime = null;
 			if ($settings->getKeepOriginalFileDate()) {
 				// Add one ms to the original file modification time to prevent the new original version from being overwritten
@@ -195,6 +203,7 @@ private function initUserEnvironment(string $uid) : void {
 			throw new NoUserException("User with uid '$uid' was not found");
 		}
 
+		$this->logger->debug('Initializing user environment for user {uid}', ['uid' => $uid]);
 		$this->userSession->setUser($user);
 		$this->filesystem->init($uid, '/' . $uid . '/files');
 	}
@@ -282,14 +291,14 @@ private function setFileVersionsLabel(File $file, string $uid, string $label): v
 
 		foreach ($versions as $version) {
 			if (!$version instanceof IMetadataVersion) {
-				$this->logger->debug('Skipping version with revision id {versionId} because "{versionClass}" is not an IMetadataVersion', ['versionId' => $revisionId, 'versionClass' => get_class($version)]);
+				$this->logger->debug('Skipping version with revision id {versionId} because "{versionClass}" is not an IMetadataVersion', ['versionClass' => get_class($version)]);
 				continue;
 			}
 
 			$versionBackend = $version->getBackend();
 
 			if (!$versionBackend instanceof IMetadataVersionBackend) {
-				$this->logger->debug('Skipping version with revision id {versionId} because its backend "{versionBackendClass}" does not implement IMetadataVersionBackend', ['versionId' => $revisionId, 'versionBackendClass' => get_class($versionBackend)]);
+				$this->logger->debug('Skipping version with revision id {versionId} because its backend "{versionBackendClass}" does not implement IMetadataVersionBackend', ['versionBackendClass' => get_class($versionBackend)]);
 				continue;
 			}
 
diff --git a/tests/Integration/OcrBackendServiceTest.php b/tests/Integration/OcrBackendServiceTest.php
index a422243..704d9e7 100644
--- a/tests/Integration/OcrBackendServiceTest.php
+++ b/tests/Integration/OcrBackendServiceTest.php
@@ -23,47 +23,64 @@
 
 namespace OCA\WorkflowOcr\Tests\Integration;
 
+use CurlHandle;
+use DomainException;
 use OCA\WorkflowEngine\Helper\ScopeContext;
 use OCA\WorkflowEngine\Manager;
 use OCA\WorkflowOcr\AppInfo\Application;
+use OCA\WorkflowOcr\BackgroundJobs\ProcessFileJob;
 use OCA\WorkflowOcr\OcrProcessors\Remote\Client\IApiClient;
 use OCA\WorkflowOcr\OcrProcessors\Remote\Client\Model\OcrResult;
 use OCA\WorkflowOcr\Operation;
 use OCA\WorkflowOcr\Service\IOcrBackendInfoService;
 use OCP\AppFramework\App;
+use OCP\BackgroundJob\IJobList;
+use OCP\IConfig;
 use OCP\WorkflowEngine\IManager;
 use Psr\Container\ContainerInterface;
 use Test\TestCase;
 
 /**
+ * Full test case for registering new OCR Workflow, uploading file and
+ * processing it via OCR Backend Service.
  * @group DB
  */
 class OcrBackendServiceTest extends TestCase {
-	private const USER = 'admin';
-	private const PASS = 'admin';
-
 	private ContainerInterface $container;
-	private Manager $manager;
+	private Manager $workflowEngineManager;
 	private IntegrationTestApiClient $apiClient;
 	private ScopeContext $context;
+	private IConfig $config;
+
 	private $operationClass = Operation::class;
+	private $oldLogLevel;
 
 	protected function setUp(): void {
 		parent::setUp();
 
 		$app = new App(Application::APP_NAME);
 		$this->container = $app->getContainer();
-		$this->manager = $this->container->get(Manager::class);
+		$this->workflowEngineManager = $this->container->get(Manager::class);
 		$this->apiClient = $this->container->get(IntegrationTestApiClient::class);
+		$this->config = $this->container->get(IConfig::class);
 		$this->context = new ScopeContext(IManager::SCOPE_ADMIN);
 
 		$this->overwriteService(IApiClient::class, $this->apiClient);
 
-		if (!$this->checkOcrBackendInstalled()) {
+		$githubActionsJob = getenv('GITHUB_JOB');
+		$isOcrBackendInstalled = $this->checkOcrBackendInstalled();
+
+		if ($githubActionsJob === 'github-php-integrationtests' && !$isOcrBackendInstalled) {
+			$this->fail('Running Github Actions Integrationtests but OCR Backend is not installed');
+			return;
+		}
+
+		if (!$isOcrBackendInstalled) {
 			$this->markTestSkipped('OCR Backend is not installed');
 			return;
 		}
 
+		$this->setNextcloudLogLevel();
 		$this->deleteTestFileIfExists();
 		$this->deleteOperation();
 	}
@@ -75,119 +92,169 @@ protected function tearDown(): void {
 
 		$this->deleteTestFileIfExists();
 		$this->deleteOperation();
+		$this->restoreNextcloudLogLevel();
+		
 		parent::tearDown();
 	}
 
-	/**
-	 * Full test case for registering new OCR Workflow, uploading file and
-	 * processing it via OCR Backend Service.
-	 */
 	public function testWorkflowOcrBackendService() {
 		$this->addOperation();
 		$this->uploadTestFile();
-		$this->runNextcloudCron();
+		$this->runOcrBackgroundJob();
 
 		$requests = $this->apiClient->getRequests();
-		$this->assertCount(1, $requests);
-		$this->assertTrue(strpos($requests[0]['fileName'], 'document-ready-for-ocr.pdf') >= 0);
-		$this->assertTrue($requests['ocrMyPdfParameters'] === '--skip-text');
+		$this->assertCount(1, $requests, 'Expected 1 OCR request');
+		$request = $requests[0];
+		$this->assertTrue(strpos($request['fileName'], 'document-ready-for-ocr.pdf') >= 0, 'Expected filename in request');
+		$this->assertTrue($request['ocrMyPdfParameters'] === '--skip-text', 'Expected OCR parameters in request');
 
 		$responses = $this->apiClient->getResponses();
-		$this->assertCount(1, $responses);
-		$this->assertTrue($responses[0] instanceof OcrResult);
+		$this->assertCount(1, $responses, 'Expected 1 OCR response');
+		$this->assertTrue($responses[0] instanceof OcrResult, 'Expected OcrResult instance, type is: ' . get_class($responses[0]));
 		/** @var OcrResult */
 		$ocrResult = $responses[0];
-		$this->assertEquals($requests[0]['fileName'], $ocrResult->getFileName());
-		$this->assertEquals('application/pdf', $ocrResult->getContentType());
-		$this->assertTrue(strpos($ocrResult->getRecognizedText(), 'This document is ready for OCR') >= 0);
+		$this->assertEquals($requests[0]['fileName'], $ocrResult->getFileName(), 'Expected filename in response to be equal to request');
+		$this->assertEquals('application/pdf', $ocrResult->getContentType(), 'Expected content type in response');
+		$this->assertTrue(strpos($ocrResult->getRecognizedText(), 'This document is ready for OCR') >= 0, 'Expected recognized text in response');
 	}
 
 	private function addOperation() {
-		$name = '';
-		$checks = [
-			0 =>
-			 [
-			 	'class' => 'OCA\\WorkflowEngine\\Check\\FileMimeType',
-			 	'operator' => 'is',
-			 	'value' => 'application/pdf',
-			 	'invalid' => false,
-			 ]
-		];
-		$operation = '';
-		$entity = "OCA\WorkflowEngine\Entity\File";
-		$events = [
-			0 => '\\OCP\\Files::postCreate',
-		];
-		$operation = $this->manager->addOperation($this->operationClass, $name, $checks, $operation, $this->context, $entity, $events);
-		$this->clearApcu();
+		// NOTE :: we're creating the workflow operation via
+		// REST API because if we'd use the manager directly, we'd
+		// face some issues because of caching etc (test ist running
+		// in another process than webserver ...)
+		$url = $this->getNextcloudOcsApiUrl() . 'apps/workflowengine/api/v1/workflows/global?format=json';
+		$json = '
+		{
+			"id":-1,
+			"class":"' . str_replace('\\', '\\\\', $this->operationClass) . '",
+			"entity":"OCA\\\\WorkflowEngine\\\\Entity\\\\File",
+			"events":["\\\\OCP\\\\Files::postCreate"],
+			"name":"",
+			"checks":[
+				{
+					"class":"OCA\\\\WorkflowEngine\\\\Check\\\\FileMimeType",
+					"operator":"is",
+					"value":"application/pdf",
+					"invalid":false
+				}
+			],
+			"operation":"",
+			"valid":true
+		}';
+		
+		$ch = curl_init($url);
+		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
+		curl_setopt($ch, CURLOPT_POST, true);
+		curl_setopt($ch, CURLOPT_POSTFIELDS, $json);
+		curl_setopt($ch, CURLOPT_HTTPHEADER, [
+			'Content-Type: application/json',
+			'OCS-APIREQUEST: true'
+		]);
+
+		$this->executeCurl($ch);
 	}
 
 	private function deleteOperation() {
-		$operations = $this->manager->getOperations($this->operationClass, $this->context);
+		$operations = $this->workflowEngineManager->getOperations($this->operationClass, $this->context);
 		foreach ($operations as $operation) {
-			$this->manager->deleteOperation($operation['id'], $this->context);
+			try {
+				$this->workflowEngineManager->deleteOperation($operation['id'], $this->context);
+			} catch (DomainException) {
+				// ignore
+			}
 		}
 		
 	}
 
 	private function uploadTestFile() {
-		$webdav_url = 'http://localhost/remote.php/dav/files/' . self::USER . '/';
-		$local_file = __DIR__ . '/testdata/document-ready-for-ocr.pdf';
-		$file = fopen($local_file, 'r');
+		$localFile = $this->getTestFileReadyForOcr();
+		$file = fopen($localFile, 'r');
 
 		$ch = curl_init();
 
-		curl_setopt($ch, CURLOPT_URL, $webdav_url . basename($local_file));
-		curl_setopt($ch, CURLOPT_USERPWD, self::USER . ':' . self::PASS);
+		curl_setopt($ch, CURLOPT_URL, $this->getNextcloudWebdavUrl() . basename($localFile));
 		curl_setopt($ch, CURLOPT_PUT, true);
 		curl_setopt($ch, CURLOPT_INFILE, $file);
-		curl_setopt($ch, CURLOPT_INFILESIZE, filesize($local_file));
+		curl_setopt($ch, CURLOPT_INFILESIZE, filesize($localFile));
 		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
 
-		curl_exec($ch);
-
-		if (curl_errno($ch)) {
-			$this->fail('Error: ' . curl_error($ch));
-		}
-
-		curl_close($ch);
+		$this->executeCurl($ch);
 		fclose($file);
 	}
 
 	private function deleteTestFileIfExists() {
-		$webdav_url = 'http://localhost/remote.php/dav/files/' . self::USER . '/';
-		$local_file = __DIR__ . '/testdata/document-ready-for-ocr.pdf';
+		$localFile = $this->getTestFileReadyForOcr();
 
 		$ch = curl_init();
 
-		curl_setopt($ch, CURLOPT_URL, $webdav_url . basename($local_file));
-		curl_setopt($ch, CURLOPT_USERPWD, self::USER . ':' . self::PASS);
+		curl_setopt($ch, CURLOPT_URL, $this->getNextcloudWebdavUrl() . basename($localFile));
 		curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'DELETE');
 		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
 
-		curl_exec($ch);
+		$this->executeCurl($ch, [404]);
+	}
+
+	private function executeCurl(CurlHandle $ch, array $allowedNonSuccessResponseCodes = []) : string|bool {
+		curl_setopt($ch, CURLOPT_USERPWD, $this->getNextcloudCredentials());
+
+		$result = curl_exec($ch);
 
 		if (curl_errno($ch)) {
-			$this->fail('Error: ' . curl_error($ch));
+			$this->fail('cURL Error: ' . curl_error($ch));
+		}
+
+		$responseCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+		if ($responseCode >= 400 && !in_array($responseCode, $allowedNonSuccessResponseCodes)) {
+			$responseBody = curl_multi_getcontent($ch);
+			$this->fail('cURL HTTP Error ' . $responseCode . ': ' . $responseBody);
 		}
 
 		curl_close($ch);
-	}
 
-	private function runNextcloudCron() {
-		global $argv;
-		$argv = [];
-		require __DIR__ . '/../../../../cron.php';
+		return $result;
 	}
 
-	private function clearApcu() {
-		if (function_exists('apcu_clear_cache')) {
-			apcu_clear_cache();
-		}
+	private function runOcrBackgroundJob() {
+		/** @var IJoblist */
+		$jobList = $this->container->get(IJobList::class);
+		$job = $jobList->getNext(false, [ProcessFileJob::class]);
+		$this->assertNotNull($job);
+		$job->start($jobList);
 	}
 
 	private function checkOcrBackendInstalled() : bool {
 		$ocrBackendInfoService = $this->container->get(IOcrBackendInfoService::class);
 		return $ocrBackendInfoService->isRemoteBackend();
 	}
+
+	private function getNextcloudWebdavUrl() : string {
+		$port = getenv('NEXTCLOUD_PORT') ?: '80';
+		$user = getenv('NEXTCLOUD_USER') ?: 'admin';
+		return 'http://localhost:' . $port . '/remote.php/dav/files/' . $user . '/';
+	}
+
+	private function getNextcloudOcsApiUrl() : string {
+		$port = getenv('NEXTCLOUD_PORT') ?: '80';
+		return 'http://localhost:' . $port . '/ocs/v2.php/';
+	}
+
+	private function getNextcloudCredentials() : string {
+		$user = getenv('NEXTCLOUD_USER') ?: 'admin';
+		$pass = getenv('NEXTCLOUD_PASS') ?: 'admin';
+		return $user . ':' . $pass;
+	}
+
+	private function getTestFileReadyForOcr() : string {
+		return __DIR__ . '/testdata/document-ready-for-ocr.pdf';
+	}
+
+	private function setNextcloudLogLevel() : void {
+		$this->oldLogLevel = $this->config->getSystemValue('loglevel', 3);
+		$this->config->setSystemValue('loglevel', 0);
+	}
+
+	private function restoreNextcloudLogLevel() : void {
+		$this->config->setSystemValue('loglevel', $this->oldLogLevel);
+	}
 }
diff --git a/tests/Unit/Service/OcrServiceTest.php b/tests/Unit/Service/OcrServiceTest.php
index 49d3938..abae085 100644
--- a/tests/Unit/Service/OcrServiceTest.php
+++ b/tests/Unit/Service/OcrServiceTest.php
@@ -26,6 +26,9 @@
 use Exception;
 use InvalidArgumentException;
 use OC\User\NoUserException;
+use OCA\Files_Versions\Versions\IMetadataVersion;
+use OCA\Files_Versions\Versions\IVersion;
+use OCA\Files_Versions\Versions\IVersionBackend;
 use OCA\Files_Versions\Versions\IVersionManager;
 use OCA\Files_Versions\Versions\Version;
 use OCA\WorkflowOcr\Exception\OcrNotPossibleException;
@@ -54,8 +57,8 @@
 use OCP\IUserSession;
 use OCP\SystemTag\ISystemTagObjectMapper;
 use PHPUnit\Framework\MockObject\MockObject;
-use PHPUnit\Framework\TestCase;
 use Psr\Log\LoggerInterface;
+use Test\TestCase;
 
 class OcrServiceTest extends TestCase {
 	/** @var IOcrProcessorFactory|MockObject */
@@ -527,15 +530,23 @@ public function testOcrSkippedIfOcrModeIsSkipFileAndResultIsEmpty() {
 		$this->ocrProcessor->expects($this->once())
 			->method('ocrFile')
 			->willThrowException(new OcrResultEmptyException('oops'));
-		$this->logger->expects($this->once())
+		$loggedSkipMessage = false;
+		$this->logger->expects($this->atLeastOnce())
 			->method('debug')
-			->with($this->stringStartsWith('Skipping empty OCR result for file with id'), ['fileId' => $fileId]);
+			->willReturnCallback(function ($message, $params) use (&$loggedSkipMessage, $fileId) {
+				if (str_contains($message, 'Skipping empty OCR result for file with id') &&
+					isset($params['fileId']) && $params['fileId'] === $fileId) {
+					$loggedSkipMessage = true;
+				}
+			});
 		$this->viewFactory->expects($this->never())
 			->method('create');
 		$this->eventService->expects($this->never())
 			->method('textRecognized');
 			
 		$this->ocrService->runOcrProcess($fileId, 'usr', $settings);
+
+		$this->assertTrue($loggedSkipMessage);
 	}
 
 	/**
@@ -549,7 +560,7 @@ public function testOcrEmptyExceptionIsThrown(int $ocrMode) {
 		$this->ocrProcessor->expects($this->once())
 			->method('ocrFile')
 			->willThrowException($ex);
-		$this->logger->expects($this->never())
+		$this->logger->expects($this->atLeastOnce())
 			->method('debug');
 		$this->viewFactory->expects($this->never())
 			->method('create');
@@ -780,6 +791,60 @@ public function dataProvider_ExceptionsToBeCaught() {
 		];
 	}
 
+	public function testSetFileVersionsLabelSkipsNonMetadataVersion(): void {
+		$file = $this->createMock(File::class);
+		$user = 'admin';
+		$version = $this->createMock(IVersion::class);
+		$userObj = $this->createMock(IUser::class);
+		$this->userManager->expects($this->once())
+			->method('get')
+			->with($user)
+			->willReturn($userObj);
+
+		$this->versionManager->expects($this->once())
+			->method('getVersionsForFile')
+			->with($userObj, $file)
+			->willReturn([$version]);
+
+		$this->logger->expects($this->once())
+			->method('debug')
+			->with('Skipping version with revision id {versionId} because "{versionClass}" is not an IMetadataVersion', ['versionClass' => get_class($version)]);
+
+		$this->invokePrivate($this->ocrService, 'setFileVersionsLabel', [$file, $user, 'label']);
+	}
+
+	public function testSetFileVersionsLabelSkipsNonMetadataVersionBackend(): void {
+		$file = $this->createMock(File::class);
+		$user = 'admin';
+		$version = $this->getMockBuilder(IMetadataVersion::class)
+			->disableOriginalConstructor()
+			->disableOriginalClone()
+			->disableArgumentCloning()
+			->disallowMockingUnknownTypes()
+			->addMethods(['getBackend'])
+			->getMockForAbstractClass();
+
+		$versionBackend = $this->createMock(IVersionBackend::class);
+		$userObj = $this->createMock(IUser::class);
+		$this->userManager->expects($this->once())
+			->method('get')
+			->with($user)
+			->willReturn($userObj);
+
+		$this->versionManager->expects($this->once())
+			->method('getVersionsForFile')
+			->with($userObj, $file)
+			->willReturn([$version]);
+
+		$version->method('getBackend')->willReturn($versionBackend);
+
+		$this->logger->expects($this->once())
+			->method('debug')
+			->with('Skipping version with revision id {versionId} because its backend "{versionBackendClass}" does not implement IMetadataVersionBackend', ['versionBackendClass' => get_class($versionBackend)]);
+
+		$this->invokePrivate($this->ocrService, 'setFileVersionsLabel', [$file, $user, 'label']);
+	}
+
 	/**
 	 * @return File|MockObject
 	 */