private void checkNonCoreGroupId ( Model model ) throws EnforcerRuleException { String groupId = model . getGroupId ( ) ; if ( groupId . equals ( CORE_GROUP_ID ) || ( groupId . startsWith ( CORE_GROUP_ID_PREFIX ) && ! groupId . equals ( CONTRIB_GROUP_ID ) && ! groupId . startsWith ( CONTRIB_GROUP_ID_PREFIX ) ) ) { throw new EnforcerRuleException ( String . format ( "Contrib extension group id have to be prefixed with [%s]" , CONTRIB_GROUP_ID ) ) ; } }
Make sure the group id does not start with org . xwiki or starts with org . xwiki . contrib .