What is the Sims 3 cheat for never die?

In The Sims 3, you can use the cheat "testingcheatsenabled true" to enable testing cheats, and then hold down the Shift key while clicking on your Sim. From the menu that appears, select "Edit Sim in Create a Sim" and change their age to "Elder," then immediately use the "Age Up" option to cycle back to "Young Adult." This effectively allows your Sim to never die, as they can continually reset their age.