code: def activate(self, user):
          
          org_user = self.organization.add_user(user, **self.activation_kwargs())
          self.invitee = user
          self.save()
          return org_user
docs: Updates the `invitee` value and saves the instance
  
          Provided as a way of extending the behavior.
  
          Args:
              user: the newly created user
  
          Returns:
              the linking organization user