code: def else_(self, result_expr):
          
          kwargs = {
              slot: getattr(self, slot)
              for slot in self.__slots__
              if slot != 'default'
          }
  
          result_expr = ir.as_value_expr(result_expr)
          kwargs['default'] = result_expr
          # Maintain immutability
          return type(self)(**kwargs)
docs: Specify
  
          Returns
          -------
          builder : CaseBuilder