Allow ShrinkWrap to overwrite existing ArchivePaths

        // Create the new archive
        final Archive<?> archive = createNewArchive();

        // Put in an asset
        final ArchivePath path = ArchivePaths.create("testPath");
        archive.add(EmptyAsset.INSTANCE, path);

        // Now try again with a new asset, and this should fail
        try {
            archive.add(new StringAsset("failContent"), path);
        } catch (final IllegalOverwriteException ioe) {
            // Good
            return;
        }