How do I make sure my custom before run task is always ran before the run/debug starts ?

I want a few generated classes to be copied to a specified folder before the main class is ran. I wanted this operation to happen without the plugin users having to configure anything. I've already extended `ConfigurationType` and having a custom implementation that does all the settings. But I'm unable configure before run task with this. 

Also is there any way to make sure that the respective before run task is always configured and not removed when running the my ConfigurationType ?