Return the sparkline.

def get(self):
        """Return the sparkline."""
        ret = sparklines(self.percents)[0]
        if self.__with_text:
            percents_without_none = [x for x in self.percents if x is not None]
            if len(percents_without_none) > 0:
                ret = '{}{:5.1f}%'.format(ret, percents_without_none[-1])
        return nativestr(ret)