public Parser paddingClause() {
        if (paddingClauseParser == null) {
           FutureParser future = scoped("paddingClause");
           paddingClauseParser = future;
           future.setParser(
               sequence(
                   token("PADDING"),
                   optional(
                       token("CHARACTER")
                   ),
                   optional(
                       token("IS")
                   ),
                   choice(
                       literal(),
                       identifier()
                   )
               )
           );
        }

        return paddingClauseParser;
    }