val uri = url.toUri()
      if (uri.host == null) return immutableListOf(Proxy.NO_PROXY)

      // Try each of the ProxySelector choices until one connection succeeds.
      val proxiesOrNull = address.proxySelector.select(uri)
      if (proxiesOrNull.isNullOrEmpty()) return immutableListOf(Proxy.NO_PROXY)

      return proxiesOrNull.toImmutableList()
    }

    connectionUser.proxySelectStart(url)

      factory.newAddress(
        proxy = Proxy.NO_PROXY,
      )
    val routeSelector = newRouteSelector(address)
    assertThat(routeSelector.hasNext()).isTrue()
    dns[uriHost] = dns.allocate(2)
    val selection = routeSelector.next()
    assertRoute(selection.next(), address, Proxy.NO_PROXY, dns.lookup(uriHost, 0), uriPort)
    assertRoute(selection.next(), address, Proxy.NO_PROXY, dns.lookup(uriHost, 1), uriPort)

  }

  @Test fun addressWithProxyToString() {
    val address = factory.newAddress(proxy = Proxy.NO_PROXY)
    assertThat(address.toString())
      .isEqualTo("Address{example.com:80, proxy=${Proxy.NO_PROXY}}")
  }

    assertThat(client.proxySelector)
      .isNotInstanceOf(NullProxySelector::class.java)
    client =
      OkHttpClient
        .Builder()
        .proxy(Proxy.NO_PROXY)
        .build()
    assertThat(client.proxy).isSameAs(Proxy.NO_PROXY)
    assertThat(client.proxySelector)
      .isInstanceOf(NullProxySelector::class.java)
    client =
      OkHttpClient
        .Builder()

import java.net.SocketAddress
import java.net.URI

/**
 * A proxy selector that always returns the [Proxy.NO_PROXY].
 */
object NullProxySelector : ProxySelector() {
  override fun select(uri: URI?): List<Proxy> {
    requireNotNull(uri) { "uri must not be null" }
    return listOf(Proxy.NO_PROXY)
  }

  override fun connectFailed(
    uri: URI?,
    sa: SocketAddress?,
    ioe: IOException?,
  ) {
  }

   *
   * Note that the list of proxies is never null, but it may be a list containing
   * only [Proxy.NO_PROXY]. This comes up in several situations:
   *
   * * If neither a proxy nor proxy selector is configured.
   * * If the proxy is configured explicitly as [Proxy.NO_PROXY].
   * * If the proxy selector returns only [Proxy.NO_PROXY].
   * * If the proxy selector returns an empty list or null.
   *

  ): Request? {
    val challenges = response.challenges()
    val request = response.request
    val url = request.url
    val proxyAuthorization = response.code == 407
    val proxy = route?.proxy ?: Proxy.NO_PROXY

    for (challenge in challenges) {
      if (!"Basic".equals(challenge.scheme, ignoreCase = true)) {
        continue
      }

      val dns = route?.address?.dns ?: defaultDns
      val auth =

  override fun select(uri: URI): List<Proxy> {
    // Don't handle 'socket' schemes, which the RI's Socket class may request (for SOCKS).
    return if (uri.scheme == "http" || uri.scheme == "https") proxies else listOf(Proxy.NO_PROXY)
  }

  override fun connectFailed(
    uri: URI,
    sa: SocketAddress,
    ioe: IOException,
  ) {
  }

        append(":")
        append(address.url.port)
      }

      if (addressHostname != socketHostname) {
        when (proxy) {
          Proxy.NO_PROXY -> append(" at ")
          else -> append(" via proxy ")
        }

        when {
          socketHostname == null -> append("<unresolved>")

import okhttp3.internal.toImmutableList

/**
 * A specification for a connection to an origin server. For simple connections, this is the
 * server's hostname and port. If an explicit proxy is requested (or [no proxy][Proxy.NO_PROXY] is
 * explicitly requested), this also includes that proxy information. For secure connections the
 * address also includes the SSL socket factory, hostname verifier, and certificate pinner.
 *