code: def add_user_email(self, user, **kwargs):
          
          # If User and UserEmail are separate classes
          if self.UserEmailClass:
              user_email = self.UserEmailClass(user=user, **kwargs)
              self.db_adapter.add_object(user_email)
  
          # If there is only one User class
          else:
              for key, value in kwargs.items():
                  setattr(user, key, value)
              user_email = user
  
          return user_email
docs: Add a UserEmail object, with properties specified in ``**kwargs``.