public Parser collationClause() {
        if (collationClauseParser == null) {
           FutureParser future = scoped("collationClause");
           collationClauseParser = future;
           future.setParser(
               sequence(
                   token("COLLATING"),
                   optional(
                       token("SEQUENCE")
                   ),
                   optional(
                       token("IS")
                   ),
                   alphabetName()
               )
           );
        }

        return collationClauseParser;
    }