val headerBlockLength = lengthWithoutPadding(length - 4, flags, padding) // - 4 for readInt().
    val headerBlock = readHeaderBlock(headerBlockLength, padding, flags, streamId)
    handler.pushPromise(streamId, promisedStreamId, headerBlock)
  }

  @Throws(IOException::class)
  private fun readPing(
    handler: Handler,
    length: Int,
    flags: Int,
    streamId: Int,
  ) {