@SuppressWarnings({"unchecked"})
    public static <T> Provider<T> seededKeyProvider() {
        return (Provider<T>) SEEDED_KEY_PROVIDER;
    }
Returns a provider that always throws exception complaining that the object
in question must be seeded before it can be injected.

@return typed provider
stroom-util/src/main/java/stroom/util/pipeline/scope/PipelineScope.java