pointerEventSource property
Allows for gestures made with human finger to be percevied as gestures made with WidgetTester, allowing to interact with a running test.
We thought we may replace this override by setting shouldPropagateDevicePointerEvents to true but it doesn't work.
See also:
Implementation
@override
TestBindingEventSource get pointerEventSource {
return TestBindingEventSource.test;
}