// Expected.
    }
    val urlConnection2 = server.url("/").toUrl().openConnection()
    val in2 = urlConnection2!!.getInputStream()
    assertThat(in2!!.read()).isEqualTo('D'.code)
    assertThat(in2.read()).isEqualTo('E'.code)
    assertThat(in2.read()).isEqualTo('F'.code)
    assertThat(in2.read()).isEqualTo(-1)
    val c0e0 = server.takeRequest()
    assertThat(c0e0.connectionIndex).isEqualTo(0)

    }
  }

  @Test fun emptyPingCallsCallback() {
    data.write("8900".decodeHex()) // Empty ping
    clientReader.processNextFrame()
    callback.assertPing(EMPTY)
  }

  @Test fun pingCallsCallback() {
    data.write("890548656c6c6f".decodeHex()) // Ping with "Hello"
    clientReader.processNextFrame()
    callback.assertPing("Hello".encodeUtf8())
  }

  // Masks are only a concern for client writers.
  private val maskKey: ByteArray? = if (isClient) ByteArray(4) else null
  private val maskCursor: Buffer.UnsafeCursor? = if (isClient) Buffer.UnsafeCursor() else null

  /** Send a ping with the supplied [payload]. */
  @Throws(IOException::class)
  fun writePing(payload: ByteString) {
    writeControlFrame(OPCODE_CONTROL_PING, payload)
  }

  /** Send a pong with the supplied [payload]. */

     * Sets the interval between HTTP/2 and web socket pings initiated by this client. Use this to
     * automatically send ping frames until either the connection fails or it is closed. This keeps
     * the connection alive and may detect connectivity failures.
     *
     * If the server does not respond to each ping with a pong within `interval`, this client will

      if (!response.isSuccessful) throw IOException("Unexpected code $response")

      for (certificate in response.handshake!!.peerCertificates) {
        println(CertificatePinner.pin(certificate))
      }
    }
  }
}

fun main() {
  CertificatePinning().run()

      if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

      for (Certificate certificate : response.handshake().peerCertificates()) {
        System.out.println(CertificatePinner.pin(certificate));
      }
    }
  }

  public static void main(String... args) throws Exception {
    new CertificatePinning().run();
  }

You can learn more about [FastAPI versions and how to pin and upgrade them](https://fastapi.tiangolo.com/deployment/versions/) for your project in the docs.

## Reporting a Vulnerability

        sink.writeInt(settings[i])
      }
      sink.flush()
    }
  }

  /**
   * Send a connection-level ping to the peer. `ack` indicates this is a reply. The data in
   * `payload1` and `payload2` opaque binary, and there are no rules on the content.
   */
  @Throws(IOException::class)
  fun ping(
    ack: Boolean,
    payload1: Int,
    payload2: Int,
  ) {
    withLock {

      settings: Settings,
    )

    /** HTTP/2 only. */
    fun ackSettings()

    /**
     * Read a connection-level ping from the peer. `ack` indicates this is a reply. The data
     * in `payload1` and `payload2` opaque binary, and there are no rules on the content.
     */
    fun ping(
      ack: Boolean,
      payload1: Int,
      payload2: Int,
    )

    /**

    the request already contains an `Accept` header.

 *  Fix: Don't crash with a `NullPointerException` if a server sends a close while we're sending a
    ping. OkHttp had a race condition bug.


## Version 4.6.0

_2020-04-28_

 *  Fix: Follow HTTP 307 and 308 redirects on methods other than GET and POST. We're reluctant to