public static String listToXml(List<DocType> docTypes) {
        return "<documents>\n" +
                docTypes.stream().map(DocType::toXml).collect(Collectors.joining("\n")) + "\n" +
                "</documents>";
    }
Definition of a document type used for testing.

@author geirst
config-model/src/test/java/com/yahoo/vespa/model/content/utils/DocType.java