Why do we need new images to test returned types? Why old images does not work?

Why do we need new images to test returned types? Why old images does not work?

There is some "if" in void refineDetectedMarkers:

    // parse output
    if(finalAcceptedIds.size() != _detectedIds.total()) {

This condition is met only one image (recover.png).

Why do we need new images to test returned types? Why old images does not work?

@alalek, current tests show no errors because they use vector<vector<Point2f> > for corners and rejectedCorners. Also, the current tests only check the number of refined corners (dimension and value are not checked).