@Override
    public void setPhysicsSpace(PhysicsSpace newSpace) {
        if (space == newSpace) {
            return;
        }
        if (added) {
            space.removeCollisionObject(this);
            added = false;
        }
        if (newSpace != null && isEnabled()) {
            newSpace.addCollisionObject(this);
            added = true;
        }
        /*
         * If this control isn't enabled, its body will be
         * added to the new space when the control becomes enabled.
         */
        space = newSpace;
    }
If enabled, add this control's body to the specified physics space. In
not enabled, alter where the body would be added. The body is removed
from any other space it's currently in.

@param newSpace where to add, or null to simply remove
jme3-jbullet/src/main/java/com/jme3/bullet/control/RigidBodyControl.java