docs: def calculateValues(self):
          """
          Overloads the calculate values method to calculate the values for
          this axis based on the minimum and maximum values, and the number
          of steps desired.
          
          :return     [<variant>, ..]
          """
          if self.maximum() <= self.minimum():
              return []
          
          max_labels = self.maximumLabelCount()
          seconds = (self.maximum() - self.minimum()).total_seconds()
          step = datetime.timedelta(0, int(round(float(seconds) / max_labels)))
          
          values = []
          value = self.minimum()
          while value <= self.maximum():
              values.append(value)
              value += step
          
          return values