Sitecore 9 Forms - Is it possible to submit forms programmatically?

We were able to successfully trigger a WFFM form submission on Sitecore 8 by following this post https://jermdavis.wordpress.com/2015/05/18/programmatic-wffm-submissions/.

However, this doesn't seem to work on Sitecore 9 anymore since the SubmitActionManager class no longer exists.

Is it still possible to submit forms progammatically in Sitecore 9?