val UNREACHABLE_ADDRESS_IPV4 = InetSocketAddress("198.51.100.1", 8080)
  val UNREACHABLE_ADDRESS_IPV6 = InetSocketAddress("::ffff:198.51.100.1", 8080)

  /** See `org.graalvm.nativeimage.ImageInfo`. */
  @JvmStatic val isGraalVmImage = System.getProperty("org.graalvm.nativeimage.imagecode") != null

  @JvmStatic
  fun headerEntries(vararg elements: String?): List<Header> = List(elements.size / 2) { Header(elements[it * 2]!!, elements[it * 2 + 1]!!) }