Feature request from navarr, posted on GitHub Jul 21, 2016
As a potential fix, I've opened Pull Request #5407. This enables the post method to send raw data as well as the previously accepted array of data.
Comment from adragus-inviqa, posted on GitHub Jul 21, 2016
I still don't know why they haven't settled for a 3rd party (Guzzle et al). Too many, maybe?
Comment from navarr, posted on GitHub Jul 21, 2016
@adragus-inviqa You probably wouldn't want a 3rd party as the Interface. Using PSR-7 perhaps - but it'd take some pretty rough refactoring, I imagine.
Didn't meant as an interface, but yeah, I forgot about PSR7. That's a no-go, indeed.
Comment from stamster, posted on GitHub Jul 21, 2016
Another very basic function missing. On Magento 1.x, anyone has idea whenever this was possible? I can bet it was.