+ private static final SubstatementValidator SUBSTATEMENT_VALIDATOR = SubstatementValidator.builder(Rfc6020Mapping
+ .EXTENSION)
+ .add(Rfc6020Mapping.ARGUMENT, 0, 1)
+ .add(Rfc6020Mapping.DESCRIPTION, 0, 1)
+ .add(Rfc6020Mapping.REFERENCE, 0, 1)
+ .add(Rfc6020Mapping.STATUS, 0, 1)
+ .build();