flutter (rethrow) When I try to restart the program it takes me to image_provider.dart (rethrow)

   Padding(
          padding: const EdgeInsets.all(8.0),
          child: Row(
            children: [
              Expanded(
                child: TextButton(
                    onPressed: () {
                      setState(() {
                        leftImageName = Random().nextInt(6) + 1;
                      });
                    },
                    child: Image.asset(
                      'images/$leftImageName.png',
                    )),
              ),
              Expanded(
                child: TextButton(
                    onPressed: () {
                      setState(() {
                        rightImageName = Random().nextInt(6) + 1;
                      });
                    },
                    child: Image.asset('images/$rightImageName.png')),
              ),
            ],
          ),
        ),

When I try to restart the program it takes me to image_provider.dart (rethrow) why ??? Is it wrong with the code or is it something else? And what is the meaning of rethrow can someone help me please