code: function initBrowser(browserOpts, opts, mode, fileGroup, cb) {
      var funcName = opts.usePromises ? 'promiseChainRemote': 'remote';
      var browser = wd[funcName](extractConnectionInfo(opts));
      browser.browserTitle = browserOpts.browserTitle;
      browser.mode = mode;
  
      browser.mode = mode;
      if (opts.testName) {
        browserOpts.name = opts.testName;
      }
      if (opts.testTags) {
        browserOpts.tags = opts.testTags;
      }
      if (opts.build) {
        browserOpts.build = opts.build;
      }
      if (opts.identifier && opts.tunneled) {
        browserOpts['tunnel-identifier'] = opts.identifier;
      }
  
      browser.init(browserOpts, function (err) {
        if (err) {
          grunt.log.error(err);
          grunt.log.error('Could not initialize browser - ' + mode);
          grunt.log.error('Make sure Sauce Labs supports the following browser/platform combo' +
                          ' on ' + color('bright yellow', 'saucelabs.com/platforms') + ': ' + browserOpts.browserTitle);
          return cb(false);
        }
        runTestsForBrowser(opts, fileGroup, browser, cb);
      });
    }
docs: Init a browser