Bug 127861 [DataBinding] Mark API provisional
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/databinding/IUpdatableTree.java
/**
	 * 
	 * @param parentElement <code>null</code> for root element
	 * @param value is the new tree element as a child of parentElement
	 * @param index
	 * @return the index where the element was added
	 */
	public int addElement(Object parentElement, int index, Object value);
	/**
	 * @param parentElement <code>null</code> for root element
	 * @param index