I did that
 for i in range(10):
        img = transforms.ToPILImage()(torch.randn(3, 600, 600))
        crop = MyRandomCrop((256, 256))
        print(crop.get_params(img, (256, 256)))

and I got
(228, 344, 256, 256)
(75, 317, 256, 256)
(190, 65, 256, 256)
(152, 243, 256, 256)
(74, 312, 256, 256)
(246, 237, 256, 256)
(137, 43, 256, 256)
(29, 186, 256, 256)
(320, 141, 256, 256)
(334, 326, 256, 256)