*  New: Build with Kotlin 1.3.41, BouncyCastle 1.62, and Conscrypt 2.2.1.
 *  Fix: Recover gracefully when a coalesced connection immediately goes unhealthy.
 *  Fix: Defer the `SecurityException` when looking up the default proxy selector.
 *  Fix: Don't use brackets formatting IPv6 host names in MockWebServer.
 *  Fix: Don't permit cache iterators to remove entries that are being written.

  val proxy: Proxy? = builder.proxy

  @get:JvmName("proxySelector")
  val proxySelector: ProxySelector =
    when {
      // Defer calls to ProxySelector.getDefault() because it can throw a SecurityException.
      builder.proxy != null -> NullProxySelector
      else -> builder.proxySelector ?: ProxySelector.getDefault() ?: NullProxySelector
    }

  @get:JvmName("proxyAuthenticator")