val bootstrapClient = OkHttpClient.Builder().cache(appCache).build()

  val dns = DnsOverHttps.Builder().client(bootstrapClient)
    .url("https://dns.google/dns-query".toHttpUrl())
    .bootstrapDnsHosts(InetAddress.getByName("8.8.4.4"), InetAddress.getByName("8.8.8.8"))
    .build()

  val client = bootstrapClient.newBuilder().dns(dns).build()
```

OkHttp is an HTTP client that’s efficient by default:

 * HTTP/2 support allows all requests to the same host to share a socket.
 * Connection pooling reduces request latency (if HTTP/2 isn’t available).
 * Transparent GZIP shrinks download sizes.
 * Response caching avoids the network completely for repeat requests.

OkHttp perseveres when the network is troublesome: it will silently recover from common connection

provided Accept-Encoding is not set previously.  Modern web servers
must choose to return Brotli responses.  n.b. It is not used for
sending requests.

```java
OkHttpClient client = new OkHttpClient.Builder()
  .addInterceptor(BrotliInterceptor.INSTANCE)
  .build();
```

```kotlin
implementation("com.squareup.okhttp3:okhttp-brotli:4.12.0")
```

===================

An [OkHttp interceptor][interceptors] which logs HTTP request and response data.

```java
HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
logging.setLevel(Level.BASIC);
OkHttpClient client = new OkHttpClient.Builder()
  .addInterceptor(logging)
  .build();
```

You can change the log level at any time by calling `setLevel()`.

To log to a custom location, pass a `Logger` instance to the constructor.

...
BUILD SUCCESSFUL in 1m 30s
63 actionable tasks: 61 executed, 2 up-to-date

```

    .addTrustedCertificate(rootCertificate.certificate())
    .build();
OkHttpClient client = new OkHttpClient.Builder()
    .sslSocketFactory(clientCertificates.sslSocketFactory(), clientCertificates.trustManager())
    .build();
```

Client Authentication
---------------------

The above scenario is representative of most TLS set ups: the client uses certificates to validate

OkHttp Coroutines
=================

Support for Kotlin clients using coroutines.

```kotlin
val call = client.newCall(request)

call.executeAsync().use { response ->
  withContext(Dispatchers.IO) {
    println(response.body?.string())
  }
}
```

This is implemented using `suspendCancellableCoroutine`
but uses the standard Dispatcher in OkHttp. This means
that by default Kotlin's Dispatchers are not used.

...
BUILD SUCCESSFUL in 1m 30s
63 actionable tasks: 61 executed, 2 up-to-date

```