@Override
    protected void onDeserialize(Deserializer buf) {
        super.onDeserialize(buf);
        locale = getUtf8(buf);
        strength = getUtf8(buf);
    }
Create an UCA node with a specific locale and strength setting.

@param arg      The argument for this function.
@param locale   The locale to use.
@param strength The strength setting to use.
searchlib/src/main/java/com/yahoo/searchlib/expression/UcaFunctionNode.java