throw (T) t; // rely on vacuous cast
    }

    static class LazyMap<K, V> extends AbstractMap<K, V> {
        private final Supplier<Map<K, V>> supplier;
        private volatile Map<K, V> delegate;

        LazyMap(Supplier<Map<K, V>> supplier) {
            this.supplier = supplier;
        }

        @Override
        public Set<Entry<K, V>> entrySet() {

                public Optional<Path> getPomFile() {
                    return Optional.ofNullable(res.getPomFile()).map(File::toPath);
                }

                @Nonnull
                @Override
                public Optional<Project> getProject() {
                    return Optional.ofNullable(res.getProject()).map(session::getProject);
                }

                @Nonnull
                @Override