Issue #1602112 by bgano: Add return docs for Connection::startTransaction()

core/lib/Drupal/Core/Database/Connection.php

@@ -820,6 +820,9 @@ public function transactionDepth() {
    * @param $name
    *   Optional name of the savepoint.
    *
+   * @return Drupal\Core\Database\Transaction
+   *   A DatabaseTransaction object.
+   *
    * @see Drupal\Core\Database\Transaction
    */
   public function startTransaction($name = '') {