In many instances, users will want to change the default behavior of the browser before the test starts, or on the fly when creating a new driver during the test run. We previously covered setting default preferences and options in the setDriver method to keep the test environment static. Now, we can alter the default preferences using the varargs parameter in Java, as an optional parameter to the setDriver method. Here are the basics:

• The varargs parameter to setDriver will be a Map<String, Object> type
• Map can be passed into the driver when creating a new browser instance, or by setting a JVM argument of mapped preferences
• JVM arguments used to pass in mapped preferences can be done in a TestNG XML file as a parameter, an IDE Run Configuration using a JVM arg, or as a -Dswitch to the command-line executable
• Each browser type will need to process the map of Desired Capabilities, preferences, and options