AbstractParser.parseExtension error

...
 <validation>
   <exception-sorter class-name="org.jboss.jca.adapters.jdbc.extensions.novendor.NullExceptionSorter"/>                      
   <stale-connection-checker class-name="org.jboss.jca.adapters.jdbc.extensions.novendor.NullStaleConnectionChecker"/>
   <valid-connection-checker class-name="org.jboss.jca.adapters.jdbc.extensions.novendor.NullValidConnectionChecker"/>
 </validation>
...

gives

aused by: javax.xml.stream.XMLStreamException: ParseError at [row,col]:[121,23]
Message: Unexpected attribute 'class-name' encountered
at org.jboss.as.controller.parsing.ParseUtils.unexpectedAttribute(ParseUtils.java:102) [jboss-as-controller-7.1.0.Alpha2-SNAPSHOT.jar:7.1.0.Alpha2-SNAPSHOT]
at org.jboss.as.controller.parsing.ParseUtils.requireSingleAttribute(ParseUtils.java:352) [jboss-as-controller-7.1.0.Alpha2-SNAPSHOT.jar:7.1.0.Alpha2-SNAPSHOT]
at org.jboss.as.controller.parsing.ParseUtils.readStringAttributeElement(ParseUtils.java:267) [jboss-as-controller-7.1.0.Alpha2-SNAPSHOT.jar:7.1.0.Alpha2-SNAPSHOT]
at org.jboss.as.connector.util.AbstractParser.parseExtension(AbstractParser.java:103)
at org.jboss.as.connector.subsystems.datasources.DsParser.parseValidationSetting(DsParser.java:1022)
at org.jboss.as.connector.subsystems.datasources.DsParser.parseDataSource(DsParser.java:719)
at org.jboss.as.connector.subsystems.datasources.DsParser.parseDataSources(DsParser.java:195)
at org.jboss.as.connector.subsystems.datasources.DsParser.parse(DsParser.java:166)
at org.jboss.as.connector.subsystems.datasources.DataSourcesExtension$NewDataSourceSubsystemParser.readElement(DataSourcesExtension.java:704)
... 14 more