Body:setBullet
Set the bullet status of a body.

There are two methods to check for body collisions:

* at their location when the world is updated (default)

* using continuous collision detection (CCD)

The default method is efficient, but a body moving very quickly may sometimes jump over another body without producing a collision. A body that is set as a bullet will use CCD. This is less efficient, but is guaranteed not to jump when moving quickly.

Note that static bodies (with zero mass) always use CCD, so your walls will not let a fast moving body pass through even if it is not a bullet.
Body:setBullet( status )
status boolean The bullet status of the body.