How do you do connecting or "rippling" somersaults?

The first person lays down on their back and the second person puts their ankles in their hands and grabs their partners ankles. The person on top needs to take a good jump and both partners need to be tight, straight, and don't let go or else it won't work (and there's a possibility of injury). It takes a few tries but it's fairly simple. Just don't let go.