}
    }

    private final List<ScopeState> values = new CopyOnWriteArrayList<>();

    public void enter() {
        values.add(0, new ScopeState());
    }

    protected ScopeState getScopeState() {
        if (values.isEmpty()) {
            throw new OutOfScopeException("Cannot access session scope outside of a scoping block");
        }
        return values.get(0);
    }

    public void exit() {

        if (stack.isEmpty()) {
            values.remove();
        }
    }

    public <T> void seed(Class<T> clazz, Provider<T> value) {
        getScopeState().seeded.put(Key.get(clazz), value);
    }

    public <T> void seed(Class<T> clazz, final T value) {
        getScopeState().seeded.put(Key.get(clazz), Providers.of(value));
    }

    public <T> Provider<T> scope(final Key<T> key, final Provider<T> unscoped) {