public Parser lockModeClause() {
        if (lockModeClauseParser == null) {
           FutureParser future = scoped("lockModeClause");
           lockModeClauseParser = future;
           future.setParser(
               sequence(
                   token("LOCK"),
                   optional(
                       token("MODE")
                   ),
                   optional(
                       token("IS")
                   ),
                   choice(
                       token("EXCLUSIVE"),
                       sequence(
                           token("MANUAL"),
                           optional(
                               lockModeWithClause()
                           )
                       ),
                       sequence(
                           token("AUTOMATIC"),
                           optional(
                               lockModeWithClause()
                           )
                       )
                   )
               )
           );
        }

        return lockModeClauseParser;
    }