method Hash.prototype.copy
Usage in Deno
```typescript import { Hash } from "node:node__crypto.d.ts"; ```
Hash.prototype.copy(options?: HashOptions): Hash
Creates a new `Hash` object that contains a deep copy of the internal state
of the current `Hash` object.
The optional `options` argument controls stream behavior. For XOF hash
functions such as `'shake256'`, the `outputLength` option can be used to
specify the desired output length in bytes.
An error is thrown when an attempt is made to copy the `Hash` object after
its `hash.digest()` method has been called.
```js
// Calculate a rolling hash.
const {
createHash,
} = await import('node:crypto');
const hash = createHash('sha256');
hash.update('one');
console.log(hash.copy().digest('hex'));
hash.update('two');
console.log(hash.copy().digest('hex'));
hash.update('three');
console.log(hash.copy().digest('hex'));
// Etc.
```
optional
options: HashOptions
`stream.transform` options