Detecting a server restart?

I want to do something if a plugin is unloaded because the server is restarting. I am probably missing it, but how can I detect if the server is in the middle of a restart?

 

Code:

if (Interface.Oxide.IsShuttingDown)
{
    //...
    return;
}

 

I knew I saw something like this before, thanks!

I completely forgot about that one, thanks!