D = HH(D, A, B, C, X[10], 9);
        C = HH(C, D, A, B, X[6], 11);
        B = HH(B, C, D, A, X[14], 15);
        A = HH(A, B, C, D, X[1], 3);
        D = HH(D, A, B, C, X[9], 9);
        C = HH(C, D, A, B, X[5], 11);
        B = HH(B, C, D, A, X[13], 15);
        A = HH(A, B, C, D, X[3], 3);
        D = HH(D, A, B, C, X[11], 9);
        C = HH(C, D, A, B, X[7], 11);
        B = HH(B, C, D, A, X[15], 15);

  internal val streams = mutableMapOf<Int, Http2Stream>()
  internal val connectionName: String = builder.connectionName
  internal var lastGoodStreamId = 0

  /** http://tools.ietf.org/html/draft-ietf-httpbis-http2-17#section-5.1.1 */
  internal var nextStreamId = if (builder.client) 3 else 2

  private var isShutdown = false

  /** For scheduling everything asynchronous. */
  private val taskRunner = builder.taskRunner

* Fix incorrect documentation example in [first steps](https://fastapi.tiangolo.com/tutorial/first-steps/). PR [#511](https://github.com/tiangolo/fastapi/pull/511) by [@IgnatovFedor](https://github.com/IgnatovFedor).