040000 tree 72d1ea4ba75b1728dbe3438f0e7208ddca1bd203	check
040000 tree 3d1df82a8cb1b2295c418c3d862263be8abc3009	examples
040000 tree 3dd6b523e210e10db017726d7eb35a5d747fdc3b	fixedbugs
040000 tree 7b0909ee93204925c5357f0f4d0506baea0df678	spec