How can I mock the CameraImage object in Flutter?

I would like to create a mock CameraImage object to be used during integration tests in Flutter. The way I will use it is by returning a mock instance of CameraImage during cameraController.startImageStream((CameraImage image) {...}).

The full CameraImage file can be found here

CameraImage definition:

class CameraImage {

  CameraImage._fromPlatformData(Map<dynamic, dynamic> data)
      : format = ImageFormat._fromPlatformData(data['format']),
        height = data['height'],
        width = data['width'],
        planes = List<Plane>.unmodifiable(data['planes']
            .map((dynamic planeData) => Plane._fromPlatformData(planeData)));

  final ImageFormat format;
  final int height;
  final int width;
  final List<Plane> planes;
}

If I try to instantiate it as CameraImage(), I get

The class 'CameraImage' doesn't have a default constructor. Try using one of the named constructors defined in 'CameraImage'

If I try to serialize it using jsonEncode() it throws an error.

What can I do?