client.dispatcher().executorService().shutdown();
  }

  @Override public void onOpen(WebSocket webSocket, Response response) {
    webSocket.send("Hello...");
    webSocket.send("...World!");
    webSocket.send(ByteString.decodeHex("deadbeef"));
    webSocket.close(1000, "Goodbye, World!");
  }

  @Override public void onMessage(WebSocket webSocket, String text) {
    System.out.println("MESSAGE: " + text);
  }

  /**
   * The HTTP <a href="https://tools.ietf.org/html/rfc6455">{@code Sec-WebSocket-Key}</a> header
   * field name.
   *
   * @since 28.0
   */
  public static final String SEC_WEBSOCKET_KEY = "Sec-WebSocket-Key";
  /**
   * The HTTP <a href="https://tools.ietf.org/html/rfc6455">{@code Sec-WebSocket-Protocol}</a>
   * header field name.
   *
   * @since 28.0
   */

            .put("SEC_CH_UA_WOW64", "Sec-CH-UA-WoW64")
            .put("SEC_WEBSOCKET_ACCEPT", "Sec-WebSocket-Accept")
            .put("SEC_WEBSOCKET_EXTENSIONS", "Sec-WebSocket-Extensions")
            .put("SEC_WEBSOCKET_KEY", "Sec-WebSocket-Key")
            .put("SEC_WEBSOCKET_PROTOCOL", "Sec-WebSocket-Protocol")
            .put("SEC_WEBSOCKET_VERSION", "Sec-WebSocket-Version")
            .put("X_WEBKIT_CSP", "X-WebKit-CSP")

            .put("SEC_CH_UA_WOW64", "Sec-CH-UA-WoW64")
            .put("SEC_WEBSOCKET_ACCEPT", "Sec-WebSocket-Accept")
            .put("SEC_WEBSOCKET_EXTENSIONS", "Sec-WebSocket-Extensions")
            .put("SEC_WEBSOCKET_KEY", "Sec-WebSocket-Key")
            .put("SEC_WEBSOCKET_PROTOCOL", "Sec-WebSocket-Protocol")
            .put("SEC_WEBSOCKET_VERSION", "Sec-WebSocket-Version")
            .put("X_WEBKIT_CSP", "X-WebKit-CSP")

import com.squareup.moshi.JsonAdapter;
import com.squareup.moshi.Moshi;
import com.squareup.moshi.ToJson;
import java.io.IOException;
import okhttp3.Call;
import okhttp3.HttpUrl;
import okhttp3.WebSocket;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.WebSocketListener;
import okio.ByteString;

/**

  @Override public void onMessage(WebSocket webSocket, String text) {
    System.out.println("onMessage: " + text);
  }

  @Override public void onClosing(WebSocket webSocket, int code, String reason) {
    webSocket.close(1000, null);
    System.out.println("onClose (" + code + "): " + reason);
  }

  @Override public void onFailure(WebSocket webSocket, Throwable t, Response response) {