How to use "Face split by edges" in 2.71.2 ?

Hi, Guys!

There is a New Modeling Tool named “split by edge” in Daily Builds.(2.71.2)

http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.72/Modeling

I have tried in many ways still don’t working.

Someone can help us to figure out it?

Thanks!

Split an n-gon the wrong way by connecting vertices with F. You then have one N-gon and an edge on top of it. It’s possible to fix that with the tool.

I get it. Thank you!