*    to use `H2_PRIOR_KNOWLEDGE` but the URL's scheme is `https:`.
 *  * Preemptive proxy authentication failed.
 *
 * Planning failures are not necessarily fatal. For example, even if we can't DNS lookup the first
 * proxy in a list, looking up a subsequent one may succeed.
 */
internal class FailedPlan(e: Throwable) : RoutePlanner.Plan {

        else -> protocol
      }
    } else {
      super.getSelectedProtocol(sslSocket)
    }

  companion object {
    val isSupported: Boolean =
      try {
        // Trigger an early exception over a fatal error, prefer a RuntimeException over Error.
        Class.forName("org.bouncycastle.jsse.provider.BouncyCastleJsseProvider", false, javaClass.classLoader)

        true
      } catch (_: ClassNotFoundException) {

        else -> protocol
      }
    } else {
      super.getSelectedProtocol(sslSocket)
    }

  companion object {
    val isSupported: Boolean =
      try {
        // Trigger an early exception over a fatal error, prefer a RuntimeException over Error.
        Class.forName("org.openjsse.net.ssl.OpenJSSE", false, javaClass.classLoader)

        true
      } catch (_: ClassNotFoundException) {
        false
      }

      init(null, arrayOf<TrustManager>(trustManager), null)
    }.socketFactory
  }

  companion object {
    val isSupported: Boolean =
      try {
        // Trigger an early exception over a fatal error, prefer a RuntimeException over Error.
        Class.forName("org.conscrypt.Conscrypt\$Version", false, javaClass.classLoader)

        when {
          // Bump this version if we ever have a binary incompatibility