@Override
    public void read(JmeImporter im) throws IOException {
        super.read(im);
        InputCapsule ic = im.getCapsule(this);
        enabled = ic.readBoolean("enabled", true);
        boolean isNull = ic.readBoolean("isNull", false);
        if (isNull) {
            setValue(null);
        }
    }
Enable or disable this <code>MatParamOverride</code>.

When disabled, the override will continue to propagate through the scene
graph like before, but it will have no effect on materials. Overrides are
enabled by default.

@param enabled Whether to enable or disable this override.
jme3-core/src/main/java/com/jme3/material/MatParamOverride.java