code: def netHours(self):
          '''
          For regular event staff, this is the net hours worked for financial purposes.
          For Instructors, netHours is calculated net of any substitutes.
          '''
          if self.specifiedHours is not None:
              return self.specifiedHours
          return self.event.duration - sum([sub.netHours for sub in self.replacementFor.all()]f netHours(self):
          '''
          For regular event staff, this is the net hours worked for financial purposes.
          For Instructors, netHours is calculated net of any substitutes.
          '''
          if self.specifiedHours is not None:
              return self.specifiedHours
          return self.event.duration - sum([sub.netHours for sub in self.replacementFor.all()])
docs: For regular event staff, this is the net hours worked for financial purposes.
          For Instructors, netHours is calculated net of any substitutes.