code: def set_range(self, minimum, maximum):
          
          self._min = minimum
          self._max = maximum
          self.on_rangeChange(minimum, maximum)
docs: Set a range.
          The range is passed unchanged to the rangeChanged member function.
          :param minimum: minimum value of the range (None if no percentage is required)
          :param maximum: maximum value of the range (None if no percentage is required)