val selection2 = routeSelector.next()
    assertThat(selection2.next()).isEqualTo(regularRoutes[1])
    assertThat(selection2.hasNext()).isFalse()

    // The second selection will contain all failed routes.
    val selection3 = routeSelector.next()
    assertThat(selection3.next()).isEqualTo(regularRoutes[0])
    assertThat(selection3.hasNext()).isFalse()

  /**
   * Invoked after proxy selection.
   *
   * Note that the list of proxies is never null, but it may be a list containing
   * only [Proxy.NO_PROXY]. This comes up in several situations:
   *
   * * If neither a proxy nor proxy selector is configured.
   * * If the proxy is configured explicitly as [Proxy.NO_PROXY].
   * * If the proxy selector returns only [Proxy.NO_PROXY].
   * * If the proxy selector returns an empty list or null.
   *

   */
  operator fun hasNext(): Boolean = hasNextProxy() || postponedRoutes.isNotEmpty()

  @Throws(IOException::class)
  operator fun next(): Selection {
    if (!hasNext()) throw NoSuchElementException()

    // Compute the next set of routes to attempt.
    val routes = mutableListOf<Route>()
    while (hasNextProxy()) {

    // Choose the first selection to do...
    int requiredChosen = chooseNextSelection(allRequired, requiredFrom, requiredTo, from, to);
    int required = allRequired[requiredChosen];

    // ...do the first selection...
    selectInPlace(required, array, from, to);

    // ...then recursively perform the selections in the range below...
    int requiredBelow = requiredChosen - 1;

 *    [proxy selector][java.net.ProxySelector] is used. It may return multiple proxies to attempt.
 *  * **IP address:** whether connecting directly to an origin server or a proxy, opening a socket
 *    requires an IP address. The DNS server may return multiple IP addresses to attempt.
 *
 * Each route is a specific selection of these options.
 */
class Route(

    // If we have a routes left, use 'em.
    if (routeSelection?.hasNext() == true) return true

    // If we haven't initialized the route selector yet, assume it'll have at least one route.
    val localRouteSelector = routeSelector ?: return true

    // If we do have a route selector, use its routes.
    return localRouteSelector.hasNext()
  }

  /**

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3

import okio.IOException

/**
 * Protocols that OkHttp implements for [ALPN][ietf_alpn] selection.
 *
 * ## Protocol vs Scheme
 *
 * Despite its name, [java.net.URL.getProtocol] returns the [scheme][java.net.URI.getScheme] (http,

 * strategies.
 *
 * <ul>
 *   <li>SafeAtomicHelper: uses Atomic FieldsUpdaters to implement synchronization
 *   <li>SynchronizedHelper: uses {@code synchronized} blocks for synchronization
 * </ul>
 *
 * To force selection of our fallback strategies we load {@link AggregateFutureState} (and all of
 * {@code com.google.common.util.concurrent}) in degenerate class loaders which make certain

   * selecting the {@code VarHandleAtomicHelper} strategy.
   */
  private static final ClassLoader NO_VAR_HANDLE =
      getClassLoader(ImmutableSet.of("java.lang.invoke.VarHandle"));

  /**
   * This classloader disallows {@link java.lang.invoke.VarHandle} and {@link sun.misc.Unsafe},
   * which will prevent us from selecting the {@code UnsafeAtomicHelper} strategy.
   */

   * selecting the {@code VarHandleAtomicHelper} strategy.
   */
  private static final ClassLoader NO_VAR_HANDLE =
      getClassLoader(ImmutableSet.of("java.lang.invoke.VarHandle"));

  /**
   * This classloader disallows {@link java.lang.invoke.VarHandle} and {@link sun.misc.Unsafe},
   * which will prevent us from selecting the {@code UnsafeAtomicHelper} strategy.
   */