Atestharness(ortestapp)isresponsibleforcreatinganobjectoftheclassbeingtestedand providing it with data. This data could come from any of several sources. Test data can beplaced directlyintoanarray withanarrayinitializer,it cancome fromtheuser atthe keyboard or it can come from a file (as you’ll see in Chapter 17). After passing this data, typically through the class’s constructor, to instantiate the object, the test harness should call the object to test its methods and manipulate its data. Gathering data in the test harness like this allows the class to manipulate data from several sources.