headers: Headers,
    inFinished: Boolean,
  ) {
    lock.assertNotHeld()

    val open: Boolean
    this.withLock {
      if (!hasResponseHeaders ||
        headers[Header.RESPONSE_STATUS_UTF8] != null ||
        headers[Header.TARGET_METHOD_UTF8] != null
      ) {
        hasResponseHeaders = true
        headersQueue += headers
      } else {
        this.source.trailers = headers
      }