Bug 141192 [Viewers] Javadoc change about multiple equal elements in StructuredViewer and AbstractTreeViewer
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
* @return whether the given element is expandable
     */
    private boolean isExpandable(Item item, TreePath parentPath, Object element) {
    	if (isTreePathContentProvider()) {
    		TreePath path;
    		if (parentPath != null) {
    			path = parentPath.createChildPath(element);
    		} else {
    			path = getTreePathFromItem(item);
    		}
    		ITreePathContentProvider cp = (ITreePathContentProvider) getContentProvider();
    		return cp != null && cp.hasChildren(path);
    	}
    	return isExpandable(element);
    }
    
    
    protected void labelProviderChanged() {
        
        Control tree = getControl();
        tree.setRedraw(false);
        
        internalRefresh(tree, getRoot(), false, true);
        tree.setRedraw(true);
    }
    /**
     * Creates a new item.
     * 
     * @param parent
     *           the parent widget