importing dot content > 256 mb fails

I can not import dot content> 256 MB due to the string limitation in V8
(according to: https://stackoverflow.com/questions/40382268/error-tostring-failed-node-js-buffer )

My code:
```
fs.readFile(argv.f, 'utf8', function(err, data) {
var graph = dot(data);
```

...

leads to:

```
dir ./graph_data/FFM/2017-05-26T09:57:20.821Z created
buffer.js:385
throw new Error('toString failed');
^

Error: toString failed
at Buffer.toString (buffer.js:385:11)
at FSReqWrap.readFileAfterClose [as oncomplete] (fs.js:378:21)
```

Any chance for an additional dot(filename) approach instead of dot(string_content) with a streaming line-by-line processing parser for avoiding this buffer limitation?

Thx