public Parser returningProcedurePhrase() {
        if (returningProcedurePhraseParser == null) {
           FutureParser future = scoped("returningProcedurePhrase");
           returningProcedurePhraseParser = future;
           future.setParser(
               sequence(
                   choice(
                       token("RETURNING"),
                       token("YIELDING"),
                       token("GIVING")
                   ),
                   dataName(),
                   optional(
                       sequence(
                           token("AS"),
                           typeName(),
                           optional(
                               attributeClause()
                           )
                       )
                   )
               )
           );
        }

        return returningProcedurePhraseParser;
    }