private static Version versionOf(Bundle bundle) {
        Object bundleVersion = bundle.getHeaders().get("Bundle-Version");
        if (bundleVersion == null) return Version.emptyVersion;
        return new Version(bundleVersion.toString());
    }
Returns the version of a bundle, as specified by Bundle-Version in the manifest
container-core/src/main/java/com/yahoo/osgi/OsgiImpl.java