* contains minimally [Protocol.HTTP_1_1].
   */
  @get:JvmName("protocols")
  val protocols: List<Protocol> = protocols.toImmutableList()

  @get:JvmName("connectionSpecs")
  val connectionSpecs: List<ConnectionSpec> =
    connectionSpecs.toImmutableList()

  @JvmName("-deprecated_url")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "url"),

  }

  @Test fun someFallbacksSupported() {
    val sslV3 =
      ConnectionSpec.Builder(ConnectionSpec.MODERN_TLS)
        .tlsVersions(TlsVersion.SSL_3_0)
        .build()
    val routePlanner = factory.newRoutePlanner(client)
    val route = factory.newRoute()
    val connectionSpecs = listOf(ConnectionSpec.MODERN_TLS, ConnectionSpec.COMPATIBLE_TLS, sslV3)
    val enabledSocketTlsVersions =
      arrayOf(

        val tlsEquipPlan = planWithCurrentOrInitialConnectionSpec(connectionSpecs, sslSocket)
        val connectionSpec = connectionSpecs[tlsEquipPlan.connectionSpecIndex]

        // Figure out the next connection spec in case we need a retry.
        retryTlsConnection = tlsEquipPlan.nextConnectionSpec(connectionSpecs, sslSocket)

        connectionSpec.apply(sslSocket, isFallback = tlsEquipPlan.isTlsFallback)

  var proxySelector: ProxySelector = RecordingProxySelector()
  var proxyAuthenticator: Authenticator = RecordingOkAuthenticator("password", null)
  var connectionSpecs: List<ConnectionSpec> =
    listOf(
      ConnectionSpec.MODERN_TLS,
      ConnectionSpec.COMPATIBLE_TLS,
      ConnectionSpec.CLEARTEXT,
    )
  var protocols: List<Protocol> =
    listOf(
      Protocol.HTTP_1_1,
    )

#### Vars and Vals

Java doesn’t have language support for properties so developers make do with getters and setters.
Kotlin does have properties and we take advantage of them in OkHttp.

 * **Address**: certificatePinner, connectionSpecs, dns, hostnameVerifier, protocols, proxy,
   proxyAuthenticator, proxySelector, socketFactory, sslSocketFactory, url
 * **Cache**: directory

      this.x509TrustManagerOrNull = trustManager
    }

    fun connectionSpecs(connectionSpecs: List<ConnectionSpec>) =
      apply {
        if (connectionSpecs != this.connectionSpecs) {
          this.routeDatabase = null
        }

        this.connectionSpecs = connectionSpecs.toImmutableList()
      }

    /**

  }

  @Test @Disabled
  fun connectionSpec() {
    val connectionSpec: ConnectionSpec = ConnectionSpec.RESTRICTED_TLS
    val tlsVersions: List<TlsVersion>? = connectionSpec.tlsVersions()
    val cipherSuites: List<CipherSuite>? = connectionSpec.cipherSuites()
    val supportsTlsExtensions: Boolean = connectionSpec.supportsTlsExtensions()
  }

  @Test @Disabled
  fun cookie() {

      .apply {
        if (connectionSpec != null) {
          connectionSpecs(
            listOf(
              ConnectionSpec.Builder(connectionSpec)
                .apply {
                  if (tlsVersion != null) {
                    tlsVersions(tlsVersion)
                  }
                  if (cipherSuites != null) {
                    cipherSuites(*cipherSuites.toTypedArray())
                  }

By default, OkHttp will attempt a `MODERN_TLS` connection.  However by configuring the client connectionSpecs you can allow a fall back to `COMPATIBLE_TLS` connection if the modern configuration fails.

```java
OkHttpClient client = new OkHttpClient.Builder()
    .connectionSpecs(Arrays.asList(ConnectionSpec.MODERN_TLS, ConnectionSpec.COMPATIBLE_TLS))
    .build();
```

import org.robolectric.RobolectricTestRunner
import org.robolectric.shadows.ShadowLog

@RunWith(RobolectricTestRunner::class)
class AndroidLoggingTest {
  val clientBuilder =
    OkHttpClient.Builder()
      .connectionSpecs(listOf(ConnectionSpec.CLEARTEXT))
      .dns {
        throw UnknownHostException("shortcircuit")
      }

  val request = Request("http://google.com/robots.txt".toHttpUrl())

  @Test
  fun testHttpLoggingInterceptor() {