code: String zone(String podName) {
          String podUrlString = String.format("%s/api/v1/namespaces/%s/pods/%s", kubernetesMaster, namespace, podName);
          String nodeName = extractNodeName(callGet(podUrlString));
  
          String nodeUrlString = String.format("%s/api/v1/nodes/%s", kubernetesMaster, nodeName);
          return extractZone(callGet(nodeUrlString));
      }
docs: Retrieves zone name for the specified {@code namespace} and the given {@code podName}.
  <p>
  Note that the Kubernetes environment provides such information as defined
  <a href="https://kubernetes.io/docs/reference/kubernetes-api/labels-annotations-taints">here</a>.
  
  @param podName POD name
  @return zone name
  @see <a href="https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.11">Kubernetes Endpoint API</a>