public void setThreadingType(ThreadingType threadingType) {
        this.threadingType = threadingType;
    }
Alter which type of threading this app state uses. Not allowed after
attaching the app state.

@param threadingType the desired type (not null, default=SEQUENTIAL)
jme3-jbullet/src/main/java/com/jme3/bullet/BulletAppState.java