Working with OS process in PHP

The Symfony Process component made it super easy to integrate with OS processes. But how we integrate with this library is still a little frustrating. We create a new process, passing in an array of arguments that makes the command we wish to run. The result of the push method will allow you to interact with the SymfONY Process - meaning you can do all sorts with the command out the other side. Can you think of any use cases for this?