add phpdoc

diff --git a/lib/private/preview.php b/lib/private/preview.php
index ba2cbd33bf39e60ee4a6bd1f51b7ab01d0648a7a..d6bff961a7334de15c69deb8a4f63f6151973984 100755 (executable)
--- a/lib/private/preview.php
+++ b/lib/private/preview.php
@@ -808,6 +808,10 @@ class Preview {
        }
 
 
+       /**
+        * @param int $fileId
+        * @return string
+        */
        private function getPreviewPath($fileId) {
                return $this->getThumbnailsFolder() . '/' . $fileId . '/';
        }