.build()
    val request =
      originalRequest.newBuilder()
        .header("Upgrade", "websocket")
        .header("Connection", "Upgrade")
        .header("Sec-WebSocket-Key", key)
        .header("Sec-WebSocket-Version", "13")
        .header("Sec-WebSocket-Extensions", "permessage-deflate")
        .build()
    call = RealCall(webSocketClient, request, forWebSocket = true)
    call!!.enqueue(

    internal val reader: Http2Reader,
  ) : Http2Reader.Handler, () -> Unit {
    override fun invoke() {
      var connectionErrorCode = ErrorCode.INTERNAL_ERROR
      var streamErrorCode = ErrorCode.INTERNAL_ERROR
      var errorException: IOException? = null
      try {
        reader.readConnectionPreface(this)
        while (reader.nextFrame(false, this)) {
        }

        headers = Headers.Builder()
      }

    /**
     * Adds [header] as an HTTP header. For well-formed HTTP [header] should contain a name followed
     * by a colon and a value.
     */
    fun addHeader(header: String) =
      apply {
        headers.add(header)
      }

    /**
     * Adds a new header with the name and value. This may be used to add multiple headers with the
     * same name.

    val derReader = DerReader(buffer)

    derReader.read("test") { header ->
      assertThat(header.tag).isEqualTo(2L)
      assertThat(header.tagClass).isEqualTo(DerHeader.TAG_CLASS_CONTEXT_SPECIFIC)
      assertThat(header.length).isEqualTo(7L)

      derReader.read("test") { header ->
        assertThat(header.tag).isEqualTo(3L)
        assertThat(header.tagClass).isEqualTo(DerHeader.TAG_CLASS_APPLICATION)

    ) {
      for (pushPromise in promises) {
        val pushedHeaders = mutableListOf<Header>()
        pushedHeaders.add(Header(Header.TARGET_AUTHORITY, url(pushPromise.path).host))
        pushedHeaders.add(Header(Header.TARGET_METHOD, pushPromise.method))
        pushedHeaders.add(Header(Header.TARGET_PATH, pushPromise.path))
        val pushPromiseHeaders = pushPromise.headers

    The upcoming Android Studio runs in a JVM but has classes from Android and that confused OkHttp!

 *  Fix: Include the header `Accept: text/event-stream` for SSE calls. This header is not added if
    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.

            override fun close() {
              closed.set(true)
              super.close()
            }
          }.buffer()
        }
      }
    val reader = body.charStream()
    assertThat(reader.read()).isEqualTo('h'.code)
    reader.close()
    assertThat(closed.get()).isTrue()
  }

  @Test
  fun sourceSeesBom() {
    val body = "efbbbf68656c6c6f".decodeHex().toResponseBody()

When writing request headers, use `header(name, value)` to set the only occurrence of `name` to `value`. If there are existing values, they will be removed before the new value is added. Use `addHeader(name, value)` to add a header without removing the headers already present.

    we ignored the problem at request-building time, only to crash later with a
    `NullPointerException`.
 *  Fix: Include a backwards-compatible `OkHttp-Response-Source` header with
    `OkUrlFactory `responses.
 *  Fix: Don't include a default User-Agent header in requests made with the Call
    API. Requests made with OkUrlFactory will continue to have a default user
    agent.
 *  New: Guava-like API to create headers:

      builder.header("", "Value")
    }
    assertFailsWith<IllegalArgumentException> {
      builder.addHeader("", "Value")
    }
  }

  @Test
  fun headerAllowsTabOnlyInValues() {
    val builder = Request.Builder()
    builder.header("key", "sample\tvalue")
    assertFailsWith<IllegalArgumentException> {
      builder.header("sample\tkey", "value")
    }
  }