protected Expression instantiate(Object oldInstance,
    Encoder out) 
{
        Class c = (Class)oldInstance;
        // As of 1.3 it is not possible to call Class.forName("int"),
        // so we have to generate different code for primitive types.
        // This is needed for arrays whose subtype may be primitive.
        if (c.isPrimitive()) {
            Field field = null;
            try {
                field = ReflectionUtils.typeToClass(c).getDeclaredField("TYPE");
            } catch (NoSuchFieldException ex) {
                System.err.println("Unknown primitive type: " + c);
            }
            return new Expression(oldInstance, field, "get", new Object[]{null});
        }
        else if (oldInstance == String.class) {
            return new Expression(oldInstance, "", "getClass", new Object[]{});
        }
        else if (oldInstance == Class.class) {
            return new Expression(oldInstance, String.class, "getClass", new Object[]{});
        }
        else {
            return new Expression(oldInstance, Class.class, "forName", new Object[]{c.getName()});
        }
}

 protected boolean mutatesTo(Object oldInstance,
    Object newInstance) 
{
        return oldInstance.equals(newInstance);
}