code: def sc_cuts_coarse(self, viewer, event, msg=True):
          
          if self.cancut:
              # adjust the cut by 10% on each end
              self._adjust_cuts(viewer, event.direction, 0.1, msg=msg)
          return True
docs: Adjust cuts interactively by setting the low AND high cut
          levels.  This function adjusts it coarsely.