only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Database/Connection.php
+++ b/core/lib/Drupal/Core/Database/Connection.php
@@ -1176,7 +1176,7 @@ public function commit() {
   }
 
   /**
-   * Retrieves an unique id from a given sequence.
+   * Retrieves an unique ID from a given sequence.
    *
    * Use this function if for some reason you can't use a serial field. For
    * example, MySQL has no ways of reading of the current value of a sequence
@@ -1184,13 +1184,14 @@ public function commit() {
    * value. Or sometimes you just need a unique integer.
    *
    * @param $existing_id
+       Maximum existing id
    *   After a database import, it might be that the sequences table is behind,
    *   so by passing in the maximum existing id, it can be assured that we
    *   never issue the same id.
    *
    * @return
    *   An integer number larger than any number returned by earlier calls and
-   *   also larger than the $existing_id if one was passed in.
+   *   also larger than $existing_id if one was passed in.
    */
   abstract public function nextId($existing_id = 0);