.build();

    final ProgressListener progressListener = new ProgressListener() {
      boolean firstUpdate = true;

      @Override public void update(long bytesRead, long contentLength, boolean done) {
        if (done) {
          System.out.println("completed");
        } else {
          if (firstUpdate) {
            firstUpdate = false;
            if (contentLength == -1) {

import okhttp3.Request;
import okhttp3.Response;
import okhttp3.WebSocketListener;
import okio.ByteString;

/**
 * API access to the <a href="https://api.slack.com/apps">Slack API</a> as an application. One
 * instance of this class may operate without a user, or on behalf of many users. Use the Slack API
 * dashboard to create a client ID and secret for this application.
 *

          scopes, "UXXXXXXXX", "My Slack Group", "TXXXXXXXX");
      client.initOauthSession(session);
    }

    client.awaitAccessToken(Timeout.NONE);
    client.startRtm();
  }