private static Map<String, Object> createVersions() {
    ArrayList<String> versions = new ArrayList<String>();
    versions.add(VERSION);

    HashMap<String, Object> res = new HashMap<String, Object>();
    res.put("supportedVersions", versions);
    res.put("version", VERSION);

    return Collections.unmodifiableMap(res);
  }
The list of supported return formats.  Always json.
hcatalog/webhcat/svr/src/main/java/org/apache/hive/hcatalog/templeton/Server.java