This class is in the `logging-interceptor` artifact.
 *  New: `Headers.Builder.addUnsafeNonAscii()` allows non-ASCII values to be added without an
    immediate exception.
 *  New: Headers can be redacted in `HttpLoggingInterceptor`.
 *  New: `Headers.Builder` now accepts dates.
 *  New: OkHttp now accepts `java.time.Duration` for timeouts on Java 8+ and Android 26+.
 *  New: `Challenge` includes all authentication parameters.

      MockResponse.Builder()
        .body("abc")
        .build(),
    )
    client =
      client.newBuilder()
        .addNetworkInterceptor(
          HttpLoggingInterceptor()
            .setLevel(HttpLoggingInterceptor.Level.BODY),
        )
        .build()
    val call =
      client.newCall(
        Request.Builder()
          .url(server.url("/"))
          .build(),
      )

 *
 * ```java
 * // The singleton HTTP client.
 * public final OkHttpClient client = new OkHttpClient.Builder()
 *     .addInterceptor(new HttpLoggingInterceptor())
 *     .cache(new Cache(cacheDir, cacheSize))
 *     .build();
 * ```
 *
 * ## Customize Your Client With newBuilder()
 *