@Override
    public void setAppProfiler(AppProfiler prof) {
        this.prof = prof;
        if (renderManager != null) {
            renderManager.setAppProfiler(prof);
        }
    }
Sets an AppProfiler hook that will be called back for
specific steps within a single update frame.  Value defaults
to null.

@param prof the profiler to use (alias created) or null for none
jme3-core/src/main/java/com/jme3/app/LegacyApplication.java