Bug 183732 [DataBinding] swallowing the exception in get/set value of the JavaBeanObservableValue
During the bidning of beans that have PropertyChangeSupport implemented but not properly initialized (i.e null), data binding "swallows" the NullPointerException only logging "Could not attach listener to".
bundles/org.eclipse.core.databinding.beans/src/org/eclipse/core/internal/databinding/internal/beans/JavaBeanObservableValue.java
return null;
		}
	}
	protected void lastListenerRemoved() {
		unhookListener();
	}
	private void unhookListener() {
		if (listenerSupport != null) {
			listenerSupport.dispose();
		}
	}
	public Object getValueType() {
		Class type = propertyDescriptor.getPropertyType();
		if (type == Object.class && overrideType != null)
			type = overrideType;
		return type;
	}
	public Object getObserved() {
		return object;
	}
	public PropertyDescriptor getPropertyDescriptor() {
		return propertyDescriptor;
	}
	
	public synchronized void dispose() {
		unhookListener();
		super.dispose();
	}
}