ServedModelInput(
            model_name=model_name,
            model_version=latest_model_version,
            workload_size="Small",
            scale_to_zero_enabled=True,
            environment_vars={}
        )

   1652 if self.name is not None: body['name'] = self.name
   1653 if self.scale_to_zero_enabled is not None: body['scale_to_zero_enabled'] = self.scale_to_zero_enabled
-> 1654 if self.workload_size is not None: body['workload_size'] = self.workload_size.value
   1655 if self.workload_type is not None: body['workload_type'] = self.workload_type.value
   1656 return body

AttributeError: 'str' object has no attribute 'value'