Extend/shorten timeline motion

I apologize if this has been asked and answered already here but I could not find it in a search.

Is there a way to select a collection of keyframes and tweens and extend them or shorten them by some factor?
This would be equivalent to the grabbing the end of a flash Motion tween and dragging it. If it gets longer the time between all keys is extended and vice versa.

I have some tweened keyframes and would like to slow down the entire sequence without moving each keyframe individually.

Thanks for any help! I really appreciate it.

This is not something that we currently have. We are already looking at possibilities for stretching/compressing keyframes in future versions.