How to nine slice a 2D SpriteRenderer?

I know this question has been asked before, but I have still not found an answer for it. In unity's official documentation, they talk about 9 slicing Sprite renders using draw mode: https://docs.unity3d.com/Manual/9SliceSprites.html They also talk about it in scripts: https://docs.unity3d.com/ScriptReference/SpriteRenderer-drawMode.html I have not been able to use either of these in the unity editor because draw mode doesn't show up in the UI and also using scripting there is no property drawMode for sprite renderers. They even talk about the feature in Unity Unite Boston 2015 https://youtu.be/muRhea-JaIM?t=4m42s

Can anyone please tell me if it is available to use in some way or if it is not implemented yet. Thanks.