Bug 234345 [Viewers] AbstractTreeViewer#getChildren(Widget,Object[]) holds doc that it is experimental
a) Remove the experimental description => Why do we need this method b) Remove the method
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
Object data = item.getData();
			if (data != null) {
				
				
				boolean expanded = expandedElements.remove(data) != null;
				if (expanded != getExpanded(item)) {
					if (expanded) {
						createChildren(item);
					}
					setExpanded(item, expanded);
				}
			}
			if (expandedElements.size() > 0) {
				internalSetExpanded(expandedElements, item);
			}
		}
	}
	/**
	 * Sets the expanded state of all items to correspond to the given set of
	 * expanded tree paths.
	 *
	 * @param expandedTreePaths
	 *            the set (element type: <code>TreePath</code>) of elements
	 *            which are expanded
	 * @param widget
	 *            the widget
	 */
	private void internalSetExpandedTreePaths(
			CustomHashtable expandedTreePaths, Widget widget,
			TreePath currentPath) {