the tableEngine field can be marked as private.

h2/src/main/org/h2/table/TableBase.java

@@ -21,7 +21,7 @@ public abstract class TableBase extends Table {
     /**
      * The table engine used (null for regular tables).
      */
-    protected final String tableEngine;
+    private final String tableEngine;
 
     private final boolean globalTemporary;