private static void ensureBundleActive(Bundle bundle) throws IllegalStateException {
        int state = bundle.getState();
        Throwable cause = null;
        if (state != Bundle.ACTIVE) {
            try {
                // Get the reason why the bundle isn't active.
                // Do not change this method to not fail if start is successful without carefully analyzing
                // why there are non-active bundles.
                bundle.start();
            } catch (BundleException e) {
                cause = e;
            }
            throw new IllegalStateException("Bundle " + bundle + " is not active. State=" + state + ".", cause);
        }
    }
Tries to resolve the given class from this class' bundle.
If unsuccessful, resolves the class from the system bundle (jdisc_core).
container-core/src/main/java/com/yahoo/osgi/OsgiImpl.java