private JsonNode getJsonNodeFromUrl(String url) throws Exception {
    ObjectMapper mapper = new ObjectMapper();
    return mapper.readTree(new URL(url));
  }
KerberosDescriptorTest tests the stack- and service-level descriptors for certain stacks
and services
ambari-server/src/test/java/org/apache/ambari/server/stack/KerberosDescriptorTest.java