Bug 126839 [DataBinding] IObservable refactoring
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/internal/databinding/NestedUpdatableCollection.java
if (innerUpdatableCollection != null) {
			innerUpdatableCollection.dispose();
		}
		currentOuterValue = null;
		databindingContext = null;
		feature = null;
		innerUpdatableCollection = null;
		innerChangeListener = null;
	}
	public int computeSize() {
		return innerUpdatableCollection == null ? 0 : innerUpdatableCollection
				.getSize();
	}
	public int addElement(Object value, int index) {
		return innerUpdatableCollection.addElement(value, index);
	}
	public void removeElement(int index) {
		innerUpdatableCollection.removeElement(index);
	}
	public void setElement(int index, Object value) {
		innerUpdatableCollection.setElement(index, value);
	}
	public Object computeElement(int index) {
		return innerUpdatableCollection.getElement(index);
	}
	public Class getElementType() {
		return elementType;
	}
}