Bug 278550 [Databinding] ObservablesManager, ObservableTracker and MapSimpleValueObservableMap lead to exception
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/ObservablesManager.java
* Disposes of this manager and all observables that it manages.
	 */
	public void dispose() {
		Set observables = new IdentitySet();
		observables.addAll(managedObservables);
		for (Iterator it = contexts.keySet().iterator(); it.hasNext();) {
			DataBindingContext context = (DataBindingContext) it.next();
			Pair trackModelsOrTargets = (Pair) contexts.get(context);
			boolean disposeTargets = ((Boolean) trackModelsOrTargets.a)
					.booleanValue();
			boolean disposeModels = ((Boolean) trackModelsOrTargets.b)
					.booleanValue();
			for (Iterator it2 = context.getBindings().iterator(); it2.hasNext();) {
				Binding binding = (Binding) it2.next();
				if (disposeTargets) {
					observables.add(binding.getTarget());
				}
				if (disposeModels) {
					observables.add(binding.getModel());
				}
			}
		}
		observables.removeAll(excludedObservables);
		for (Iterator it = observables.iterator(); it.hasNext();) {
			IObservable observable = (IObservable) it.next();
			observable.dispose();
		}
	}
}