Finally, the next example shows how to set the optional browser preferences as a JVM argument using the TestNG parameter attribute in the suite XML file:

// pass in the key:value pairs as a runtime argument
-Dbrowserprefs=applicationCacheEnabled:false,
               network.cookie.cookieBehavior:0

// pass in the key:value pairs as a TestNG XML parameter
<test name="Selenium TestNG Test Suite">
    <parameter name="browser" value="chrome" />
    <parameter name="platform" value="Windows 10" />
    <parameter name="browserPrefs" value="intl.accept_languages:fr" />

    <classes>
        <class name="com.myproject.MyTest" />
    </classes>
</test>

// for convenience, create a setPreferences method
// to build the map to pass into the driver
public Map<String, Object> setPreferences() {
    Map<String, Object> prefsMap = new HashMap<String, Object>();
    List<String> allPrefs = Arrays.asList(
                 System.getProperty("browserPrefs").split(",", -1));

    // extract the key/value pairs and pass to map...
    for ( String getPref : allPrefs ) {
        prefsMap.put(getPref.split(":")[0], getPref.split(":")[1]);
    }

    return prefsMap;
}

// set JVM arg, call this method on-the-fly, create new driver
if ( System.getProperty("browserPrefs") != null ) {
    CreateDriver.getInstance().setDriver("firefox",
                                         "Windows 10",
                                         "local",
        CreateDriver.getInstance().setBrowserPrefs()
                                         );
}