@Override
    public Map<String, Map<String, String>> getProperties(String mapPrefix, String mapPredicate, String... selection)  {
      Map<String, Object> args = new TreeMap<>();
      args.put("prefix", mapPrefix);
      if (mapPredicate != null) {
        args.put("predicate", mapPredicate);
      }
      if (selection != null && selection.length > 0) {
        args.put("selection", selection);
      }
      try {
        Object result = clientCall(jwt, url, "POST", args);
        return result instanceof Map? (Map<String, Map<String, String>>) result : null ;
      } catch(IOException xio) {
        return null;
      }
    }
A property client that uses http as transport.
standalone-metastore/metastore-server/src/test/java/org/apache/hadoop/hive/metastore/properties/HMSServletTest.java