How to use the chimp.port function in chimp

var setupBrowser = function setupBrowser() {
      log.debug('[chimp][helper] getting browser');

      var webdriverioConfigOptions = JSON.parse(process.env['chimp.webdriverio']);
      var webdriverioOptions = (0, _deepExtend2.default)(webdriverioConfigOptions, {
        desiredCapabilities: {
          browserName: (0, _environmentVariableParsers.parseNullableString)(process.env['chimp.browser']),
          platform: (0, _environmentVariableParsers.parseNullableString)(process.env['chimp.platform']),
          name: (0, _environmentVariableParsers.parseNullableString)(process.env['chimp.name']),
          version: (0, _environmentVariableParsers.parseNullableString)(process.env['chimp.version']),
          deviceName: (0, _environmentVariableParsers.parseNullableString)(process.env['chimp.deviceName'])
        },
        user: (0, _environmentVariableParsers.parseNullableString)(process.env['chimp.user'] || process.env.SAUCE_USERNAME),
        key: (0, _environmentVariableParsers.parseNullableString)(process.env['chimp.key'] || process.env.SAUCE_ACCESS_KEY),
        host: (0, _environmentVariableParsers.parseNullableString)(process.env['chimp.host']),
        port: (0, _environmentVariableParsers.parseNullableInteger)(process.env['chimp.port']),
        logLevel: booleanHelper.isTruthy(process.env['chimp.debug']) ? 'verbose' : webdriverioConfigOptions.logLevel,
        sync: (0, _environmentVariableParsers.parseBoolean)(process.env['chimp.sync'])
      });

      global.sessionManager = new SessionFactory((0, _assign2.default)(_.pick(webdriverioOptions, 'host', 'port', 'user', 'key'), {
        browser: webdriverioOptions.desiredCapabilities.browserName,
        deviceName: webdriverioOptions.desiredCapabilities.deviceName
      }));

      if (booleanHelper.isTruthy(process.env['chimp.watch'])) {
        webdriverioOptions.desiredCapabilities.applicationCacheEnabled = false;
      }

      log.debug('[chimp][helper] webdriverioOptions are ', (0, _stringify2.default)(webdriverioOptions));
      var remoteSession = void 0;
      if ((0, _environmentVariableParsers.parseNullableInteger)(process.env['CUCUMBER_BROWSERS'])) {

}

      if (self.options.seleniumDebug) {
        processHelper.logOutputs('selenium', self.child);
      }

      process.on('exit', function () {
        log.debug('[chimp][selenium] process exit event detected. Stopping process');
        self.stop(function () {
          log.debug('[chimp][selenium] process exit event stop complete');
        });
      });

      self.sessionManager = new SessionManager({
        host: process.env['chimp.host'],
        port: process.env['chimp.port'],
        browser: process.env['chimp.browser'],
        deviceName: process.env['chimp.deviceName']
      });

      callback(null);
    });
  });

}

      if (self.options.seleniumDebug) {
        processHelper.logOutputs('selenium', self.child);
      }

      process.on('exit', function () {
        log.debug('[chimp][selenium] process exit event detected. Stopping process');
        self.stop(function () {
          log.debug('[chimp][selenium] process exit event stop complete');
        });
      });

      self.sessionManager = new SessionManager({
        host: process.env['chimp.host'],
        port: process.env['chimp.port'],
        browser: process.env['chimp.browser'],
        deviceName: process.env['chimp.deviceName']
      });

      callback(null);
    });
  });

const webdriverioConfigOptions = JSON.parse(process.env['chimp.webdriverio']);
      const webdriverioOptions = merge(
        webdriverioConfigOptions,
        {
          desiredCapabilities: {
            browserName: parseNullableString(process.env['chimp.browser']),
            platform: parseNullableString(process.env['chimp.platform']),
            name: parseNullableString(process.env['chimp.name']),
            version: parseNullableString(process.env['chimp.browserVersion']),
            deviceName: parseNullableString(process.env['chimp.deviceName']),
          },
          user: parseNullableString(process.env['chimp.user'] || process.env.SAUCE_USERNAME),
          key: parseNullableString(process.env['chimp.key'] || process.env.SAUCE_ACCESS_KEY),
          host: parseNullableString(process.env['chimp.host']),
          port: parseNullableInteger(process.env['chimp.port']),
          logLevel: booleanHelper.isTruthy(process.env['chimp.debug']) ?
            'verbose' : webdriverioConfigOptions.logLevel,
          sync: parseBoolean(process.env['chimp.sync']),
        }
      );

      global.sessionManager = new SessionFactory(Object.assign(
        _.pick(webdriverioOptions, 'host', 'port', 'user', 'key'),
        {
          browser: webdriverioOptions.desiredCapabilities.browserName,
          deviceName: webdriverioOptions.desiredCapabilities.deviceName,
        }
      ));

      if (booleanHelper.isTruthy(process.env['chimp.watch'])) {
        webdriverioOptions.desiredCapabilities.applicationCacheEnabled = false;