type RunSnapshotState =
  | Readonly<{ type: "Running" }>
  | Readonly<{ type: "Disposing" }>
  | Readonly<{
      result:
        | Readonly<{ value: unknown; ok: true }>
        | Readonly<{ error: unknown; ok: false }>;
      type: "Settled";
      outcome:
        | Readonly<{ value: unknown; ok: true }>
        | Readonly<{ error: unknown; ok: false }>;
    }>;