image crop doesn't work

[Oceania2018]

        [TestMethod]
        public void imcrop()
        {
            var img = cv2.imread(imgSolar);
            var cropped = cv2.imcrop(img, (1, 3), (1, 3));
            cv2.imwrite("cropped.jpg", cropped);
        }

python version: https://www.pyimagesearch.com/2014/01/20/basic-image-manipulations-in-python-and-opencv-resizing-scaling-rotating-and-cropping/

[kerryjiang]

There is no native lib of OpenCV for Mac OS X.