```typescript
import { types } from "node:node__util.d.ts";
```
isBigUint64Array(value: unknown): value is BigUint64Array
Returns `true` if the value is a `BigUint64Array` instance.
```js
util.types.isBigUint64Array(new BigInt64Array()); // Returns false
util.types.isBigUint64Array(new BigUint64Array()); // Returns true
```