private static void addNode(ConfigDefinition def, LeafCNode.EnumLeaf leaf) {
        if (leaf.getDefaultValue() != null) {
            def.addEnumDef(leaf.getName(), List.of(leaf.getLegalValues()), leaf.getDefaultValue().getValue());
        } else {
            def.addEnumDef(leaf.getName(), List.of(leaf.getLegalValues()), null);
        }
    }
@param def a ConfigDefinition object
@param node the node to be added to the config definition
config/src/main/java/com/yahoo/vespa/config/ConfigDefinitionBuilder.java