public void removeClass(String name) { Class<?> clazz = classes.remove(name); try { if ((clazz != null) && (ConfigurationSerializable.class.isAssignableFrom(clazz))) { Class<? extends ConfigurationSerializable> serializable = (Class<? extends ConfigurationSerializable>) clazz; ConfigurationSerialization.unregisterClass(serializable); } } catch (NullPointerException ex) { // Boggle! // (Native methods throwing NPEs is not fun when you can't stop it before-hand) } }