@Override
    public void read(JmeImporter im) throws IOException {
        InputCapsule ic = im.getCapsule(this);
        enabled = ic.readBoolean("enabled", true);
        spatial = (Spatial) ic.readSavable("spatial", null);
    }
To be implemented in subclass.

@param rm the RenderManager rendering the controlled Spatial (not null)
@param vp the ViewPort being rendered (not null)
jme3-core/src/main/java/com/jme3/scene/control/AbstractControl.java