*
   * @param associatedStreamId the stream that triggered the sender to create this stream.
   * @param out true to create an output stream that we can use to send data to the remote peer.
   *     Corresponds to `FLAG_FIN`.
   */
  @Throws(IOException::class)
  fun pushStream(
    associatedStreamId: Int,
    requestHeaders: List<Header>,
    out: Boolean,
  ): Http2Stream {