check(type == -1)
      this.type = Http2.TYPE_SETTINGS
      this.ack = true
    }

    override fun headers(
      inFinished: Boolean,
      streamId: Int,
      associatedStreamId: Int,
      headerBlock: List<Header>,
    ) {
      check(type == -1)
      this.type = Http2.TYPE_HEADERS
      this.inFinished = inFinished
      this.streamId = streamId
      this.associatedStreamId = associatedStreamId

    }

    /**
     * Checks if `expected` and `observed` are equal when viewed as a set and headers are
     * deduped.
     *
     * TODO: See if duped headers should be preserved on decode and verify.
     */
    private fun assertSetEquals(
      message: String,
      expected: List<Header>,
      observed: List<Header>,
    ) {
      assertThat(LinkedHashSet(observed), message)
        .isEqualTo(LinkedHashSet(expected))

    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)

      Request.Builder()
        .url(server.url("/"))
        .header("", "A")
        .build()
    }
  }

  @Test
  fun emptyResponseHeaderNameIsLenient() {
    val headers = Headers.Builder()
    addHeaderLenient(headers, ":A")
    server.enqueue(
      MockResponse(
        headers = headers.build(),
        body = "body",
      ),
    )

 */
internal interface DerAdapter<T> {
  /** Returns true if this adapter can read [header] in a choice. */
  fun matches(header: DerHeader): Boolean

  /**
   * Returns a value from this adapter.
   *
   * This must always return a value, though it doesn't necessarily need to consume data from
   * [reader]. For example, if the reader's peeked tag isn't readable by this adapter, it may return
   * a default value.
   *

    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.

      // Read the header.
      val header = Buffer()
      fileOperator.read(0, header, FILE_HEADER_SIZE)
      val prefix = header.readByteString(PREFIX_CLEAN.size.toLong())
      if (prefix != PREFIX_CLEAN) throw IOException("unreadable cache file")
      val upstreamSize = header.readLong()
      val metadataSize = header.readLong()

      // Read the metadata.

   */
  private fun decodeHeaderAsJavaNetCookies(
    url: HttpUrl,
    header: String,
  ): List<Cookie> {
    val result = mutableListOf<Cookie>()
    var pos = 0
    val limit = header.length
    var pairEnd: Int
    while (pos < limit) {
      pairEnd = header.delimiterOffset(";,", pos, limit)
      val equalsSign = header.delimiterOffset('=', pos, pairEnd)

          url = "https://url-host.com:${server.port}/".toHttpUrl(),
          headers = headersOf("Host", "header-host"),
        ),
      )
    val response = call.execute()
    assertThat(response.isSuccessful).isTrue()

    val recordedRequest = server.takeRequest()
    assertThat(recordedRequest.requestUrl!!.host).isEqualTo("header-host")
    assertThat(recordedRequest.handshakeServerNames).containsExactly("url-host.com")

    assertThat(recorded.headers["Connection"]).isEqualTo("Upgrade, HTTP2-Settings")
    if (PlatformVersion.majorVersion < 19) {
      assertThat(recorded.headers["Content-Length"]).isEqualTo("0")
    }
    assertThat(recorded.headers["HTTP2-Settings"]).isNotNull()
    assertThat(recorded.headers["Upgrade"]).isEqualTo("h2c") // HTTP/2 over plaintext!
    assertThat(recorded.headers["User-Agent"]!!).matches(Regex("Java-http-client/.*"))