# Isolation

`import { Isolation } from "destack:test";`

Test runtime isolation mode.

```ds title="Isolation"
export enum Isolation {
    None = 1,
    Runtime = 2,
    World = 3,
}
```

[language/library/src/test/options.ds:27:34](https://github.com/destack-sh/destack/blob/main/language/library/src/test/options.ds#L27-L34)

## Variants

### `None = 1`

Run in the current runtime.

### `Runtime = 2`

Run in a fresh runtime.

### `World = 3`

Run in a fresh world.