I want a gameover function to run when a physics body touches this.physics.p2.walls.bottom

[kriket]

I want a gameover function to run when a physics body touches this.physics.p2.walls.bottom. In arcade physics, this can be accomplished by "Touching". But how do I achieve this in P2. The only function I found that did anything similar was "onBeginContact" but that won't work with just the bottom wall alone. 

 

So is there something like this built-in p2 like it is in arcade? Looked at docs for 15 mins but still looking for help.