:type series: List
        :type exponent: int
        :rtype: float

def run(self, series, exponent=None):
        '''
        :type series: List
        :type exponent: int
        :rtype: float
        '''
        try:
            return self.calculateHurst(series, exponent)
        except Exception as e:
            print("   Error: %s" % e)