vice is left idle, it will first dim, then turn off the screen, and
ultimately turn off the CPU. This prevents the device's battery from quickly getting
drained. Yet there are times when your application might require a different behavior:</p>

<ul>

<li>Apps such as games or movie apps may need to keep the screen turned on.</p>

<li>Other applications may not need the screen to remain on, but they may require the CPU
 to keep running until a critical operation finishes.</p>

</ul>

<p>
This class describes