@Override
        public void log(Level level, String message) {
            if (Set.of(SEVERE, WARNING, INFO).contains(level))
                msgs.add(new Pair<>(level, message));
        }
Utility functions for testing the ContainerModelBuilder. Note that XML validation will
not be done when using this class

@author gjoranv
config-model/src/test/java/com/yahoo/vespa/model/container/xml/ContainerModelBuilderTestBase.java