Bug 315281 update copyrights for 3.6
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/wizards/CommonWizardDescriptorManager.java
}
		synchronized (INSTANCE) {
			if (!isInitialized) {
				INSTANCE.init();
				isInitialized = true;
			}
		}
		return INSTANCE;
	}
	private void init() {
		new CommonWizardRegistry().readRegistry();
	}
	private void addCommonWizardDescriptor(CommonWizardDescriptor aDesc) {
		if (aDesc == null) {
			return;
		} else if(aDesc.getWizardId() == null) {
			NavigatorPlugin.logError(0, "A null wizardId was supplied for a commonWizard in " + aDesc.getNamespace(), null); 
		}
		synchronized (commonWizardDescriptors) {
			Set descriptors = (Set) commonWizardDescriptors.get(aDesc
					.getType());
			if (descriptors == null) { 
				commonWizardDescriptors.put(aDesc.getType(), descriptors = new HashSet());
			}
			if (!descriptors.contains(aDesc)) {
				descriptors.add(aDesc);
			}
		}
	}
	/**