method FileHandle.close
Usage in Deno
```typescript import { type FileHandle } from "node:node__fs--promises.d.ts"; ```
FileHandle.close(): Promise<void>
Closes the file handle after waiting for any pending operation on the handle to
complete.
```js
import { open } from 'node:fs/promises';
let filehandle;
try {
filehandle = await open('thefile.txt', 'r');
} finally {
await filehandle?.close();
}
```
Promise<void>
Fulfills with `undefined` upon success.