def METHOD_NAME(self, setting, value, fitsimage):
    """
    This method is called when the cut level values (lo/hi) have
    changed in a channel.  We adjust them in the ColorBar to match.
    """
    if not self.gui_up:
        return
    if fitsimage != self.fv.getfocus_viewer():
        # values have changed in a channel that doesn't have the focus
        return False
    loval, hival = value
    self.colorbar.set_range(loval, hival)