Sample: show uses for EventHistoryCollector

We don't have many samples demonstrating the use of Events. I would like to see a sample that allowed a script to listen for multiple VM power on events and take action on the VM power on events asynchronously.

What I mean by that is in the sample create/find 3 VM. Power them on 1, 2, 3 and if 2 powers up first do something to it (like touch a guest file or answer a VM question or something) then go back to listening for 1 and 3's finished power on task.