to take advantage of sweet Kotlin features.

#### Credentials.basic()

The username and password parameters to `Credentials.basic()` are now non-null strings. In OkHttp
3.x, null would yield a username or password of "null".

#### HttpUrl.queryParameterValues()

The return type of `HttpUrl.queryParameterValues()` is `List<String?>`. Lists that may contain null

* 次に、ミドルウェアはアプリケーション (の *path operation*) によって生成された**レスポンス**を受け取ります。
* その**レスポンス**に対して何かを実行したり、必要なコードを実行したりできます。
* そして、**レスポンス**を返します。

/// note | "技術詳細"

`yield` を使った依存関係をもつ場合は、終了コードはミドルウェアの *後に* 実行されます。

バックグラウンドタスク (後述) がある場合は、それらは全てのミドルウェアの *後に* 実行されます。

///

## ミドルウェアの作成

ミドルウェアを作成するには、関数の上部でデコレータ `@app.middleware("http")` を使用します。

ミドルウェア関数は以下を受け取ります:

  /**
   * Returns a big-endian representation of {@code value} in a 2-element byte array; equivalent to
   * {@code ByteBuffer.allocate(2).putChar(value).array()}. For example, the input value {@code
   * '\\u5432'} would yield the byte array {@code {0x54, 0x32}}.
   *
   * <p>If you need to convert and concatenate several values (possibly even of different types),
   * use a shared {@link java.nio.ByteBuffer} instance, or use {@link

  /**
   * Returns a big-endian representation of {@code value} in a 2-element byte array; equivalent to
   * {@code ByteBuffer.allocate(2).putShort(value).array()}. For example, the input value {@code
   * (short) 0x1234} would yield the byte array {@code {0x12, 0x34}}.
   *
   * <p>If you need to convert and concatenate several values (possibly even of different types),
   * use a shared {@link java.nio.ByteBuffer} instance, or use {@link

  /**
   * Returns a big-endian representation of {@code value} in a 2-element byte array; equivalent to
   * {@code ByteBuffer.allocate(2).putShort(value).array()}. For example, the input value {@code
   * (short) 0x1234} would yield the byte array {@code {0x12, 0x34}}.
   *
   * <p>If you need to convert and concatenate several values (possibly even of different types),
   * use a shared {@link java.nio.ByteBuffer} instance, or use {@link

 *
 * <p>Implementations of this interface are expected to be thread-safe, and can be safely accessed
 * by multiple concurrent threads.
 *
 * <p>When evaluated as a {@link Function}, a cache yields the same result as invoking {@link
 * #getUnchecked}.
 *
 * @param <K> the type of the cache's keys, which are not permitted to be null
 * @param <V> the type of the cache's values, which are not permitted to be null

  static void awaitWaiting(Thread t) {
    while (true) {
      Thread.State state = t.getState();
      switch (state) {
        case RUNNABLE:
        case BLOCKED:
          Thread.yield();
          break;
        case WAITING:
          return;
        default:
          throw new AssertionError("unexpected state: " + state);
      }
    }
  }

	// non-profitable and allows to confirm that spinning does not do harm.
	// To achieve this we create excess of goroutines most of which do local work.
	// These goroutines yield during local work, so that switching from
	// a blocked goroutine to other goroutines is profitable.
	// As a matter of fact, this benchmark still triggers some spinning in the mutex.
	m := NewDRWMutex(ds, "")

        localhostIpv6,
        TestUtil.UNREACHABLE_ADDRESS_IPV4.address,
      )
    serverIpv4.protocols = listOf(Protocol.H2_PRIOR_KNOWLEDGE)
    serverIpv6.protocols = listOf(Protocol.H2_PRIOR_KNOWLEDGE)

    // Yield the first IP address so the second IP address completes first.
    val firstConnectLatch = CountDownLatch(1)
    val socketFactory =
      object : DelegatingSocketFactory(SocketFactory.getDefault()) {
        var first = true

          // wake up spuriously.
          restoreInterruptedBit = Thread.interrupted() || restoreInterruptedBit;
          LockSupport.park(blocker);
        }
      } else {
        Thread.yield();
      }
      state = get();
    }
    if (restoreInterruptedBit) {
      currentThread.interrupt();
    }
    /*