code: def defaultData(self, defaultData):
          
          self._defaultData = self._enforceDataType(defaultData) # Enforce to be a QFont
          self.familyCti.defaultData = fontFamilyIndex(self.defaultData,
                                                       list(self.familyCti.iterConfigValues))
          self.pointSizeCti.defaultData = self.defaultData.pointSize()
          self.weightCti.defaultData = self.defaultData.weight()
          self.italicCti.defaultData = self.defaultData.italic()
docs: Sets the data of this item.
              Does type conversion to ensure default data is always of the correct type.