@ParametricNullness
    public T next() {
      if (done) {
        throw new NoSuchElementException();
      }
      done = true;
      return value;
    }
  }

  /**
   * Adapts an {@code Enumeration} to the {@code Iterator} interface.
   *
   * <p>This method has no equivalent in {@link Iterables} because viewing an {@code Enumeration} as

   *   <li>Return a {@code ClosingFuture}. To turn a {@link ListenableFuture} into a {@code
   *       ClosingFuture} call {@link #from(ListenableFuture)}.
   *   <li>In case this step doesn't create new closeables, you can adapt an API that returns a
   *       {@link ListenableFuture} to return a {@code ClosingFuture} by wrapping it with a call to
   *       {@link #withoutCloser(AsyncFunction)}
   * </ul>
   *
   * <p>Example usage:
   *

 * AsyncCacheLoader.asyncLoad}</a> must return a {@code CompletableFuture}. Users of Guava's {@link
 * com.google.common.util.concurrent.ListenableFuture} can adapt between the two {@code Future}
 * types by using <a href="https://github.com/lukas-krecan/future-converter#java8-guava">{@code
 * net.javacrumbs.futureconverter.java8guava.FutureConverter}</a>.
 *

        putEnv(env, Context.SECURITY_PRINCIPAL, principal);
        putEnv(env, Context.SECURITY_CREDENTIALS, credntials);
        if (providerUrl != null && providerUrl.startsWith("ldaps://")) {
            putEnv(env, Context.SECURITY_PROTOCOL, "ssl");
        }
        return env;
    }

    /**
     * Puts a key-value pair to the environment.
     *

 * AsyncCacheLoader.asyncLoad}</a> must return a {@code CompletableFuture}. Users of Guava's {@link
 * com.google.common.util.concurrent.ListenableFuture} can adapt between the two {@code Future}
 * types by using <a href="https://github.com/lukas-krecan/future-converter#java8-guava">{@code
 * net.javacrumbs.futureconverter.java8guava.FutureConverter}</a>.
 *

* Adding nodeports services to quota ([#22154](https://github.com/kubernetes/kubernetes/pull/22154), [@sdminonne](https://github.com/sdminonne))
* e2e: adapt kubelet_perf.go to use the new summary metrics API ([#24003](https://github.com/kubernetes/kubernetes/pull/24003), [@yujuhong](https://github.com/yujuhong))