return path;
    }

    @Override
    public ModelType<C> getType() {
        return type;
    }

    private Collection<E> getBackingValue() {
        return Cast.uncheckedCast(modelNode.getPrivateData(Collection.class));
    }

    private void setBackingValue(Collection<E> values) {
        if (state.isCanMutate()) {
            modelNode.setPrivateData(Collection.class, values);
        }
    }

            @Override
            public NamedEntityInstantiator<T> transform(MutableModelNode modelNode) {
                return modelNode.getPrivateData(instantiatorTypeOf(baseItemModelType));
            }
        });
    }

                }
            })
        }
        registry.registerInstance("thing", new Bean(value: "created"))

        expect:
        registry.atState(ModelPath.path("thing"), state).getPrivateData(ModelType.of(Bean))?.value == expected

        where:
        state                           | expected
        ModelNode.State.Registered      | null
        ModelNode.State.Discovered      | null