Attaching buffer for multipart forms

I'm trying to test file uploads, and it works when having a path to the file. Here, the file is 10MB, and I get the 'file too large' error on the backend server as expected. But if I try using a Buffer instead of the same size 10MB, there's no file too large error. Am I using Buffers in the right way in multipart forms here?

```js
// works
.attach('file', pathToFile)

// doesn't work
.attach('file', Buffer.from('a'.repeat(10000000)))
```