* well. Any subsequent {@code getXXX} method invocation attempt will fail with {@link IllegalStateException}.
 */
public class RepositorySystemSupplier implements Supplier<RepositorySystem> {
    private final AtomicBoolean closed = new AtomicBoolean(false);

    public RepositorySystemSupplier() {}

    private void checkClosed() {
        if (closed.get()) {
            throw new IllegalStateException("Supplier is closed");
        }