clearAllTestValues method Null safety
Delete any test value properties that have been set on this TestWindow as well as its platformDispatcher.
After calling this, the real SingletonFlutterWindow and ui.PlatformDispatcher values are reported again.
If desired, clearing of properties can be done on an individual basis, e.g., clearLocaleTestValue().
Implementation
void clearAllTestValues() {
clearDevicePixelRatioTestValue();
clearPaddingTestValue();
clearDisplayFeaturesTestValue();
clearPhysicalSizeTestValue();
clearViewInsetsTestValue();
platformDispatcher.clearAllTestValues();
}