Prompt 4.4 Wallpaper Picker

I was wondering if anyone knows how to get the wallpaper picker from Google now, i think this would be useful for if people made launchers but as far as i know only one person has been able to do it, a guy who made the Inspire Launcher. Does anyone think they could release the code or something for developers?

also, I think Ive found the activity the new launcher uses, if any developers out there want to try and test it out here's the link to the java activity

https://android.googlesource.com/pla...rActivity.java

If anyone doesn't know which wallpaper picker i mean here is an image of it below