Modules to enable.
Test classes extending this class, and any classes in the hierarchy up to this class, may specify individual lists of modules to enable by setting this property. The values of all properties in all classes in the hierarchy are merged.
Unlike UnitTestBase::setUp(), any modules specified in the $modules property are automatically loaded and set as the fixed module list.
Unlike WebTestBase::setUp(), the specified modules are loaded only, but not automatically installed. Modules need to be installed manually, if needed.
Type: array
DrupalUnitTestBase::enableModules()
public static $modules = array();