if (platform == "jdk8alpn") {
    // Add alpn-boot on Java 8 so we can use HTTP/2 without a stable API.
    val alpnBootVersion = alpnBootVersion()
    if (alpnBootVersion != null) {
      val alpnBootJar = configurations.detachedConfiguration(
        dependencies.create("org.mortbay.jetty.alpn:alpn-boot:$alpnBootVersion")
      ).singleFile
      tasks.withType<Test> {
        jvmArgs("-Xbootclasspath/p:${alpnBootJar}")
      }