Bug 141192 [Viewers] Javadoc change about multiple equal elements in StructuredViewer and AbstractTreeViewer
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
internalExpand(treePath, false);
            expandedTreePaths.put(treePath, treePath);
        }
        
        
        
        
        internalSetExpandedTreePaths(expandedTreePaths, getControl(), new TreePath(new Object[0]));
    }
	/**
     * Sets whether the node corresponding to the given element or tree path is expanded or
     * collapsed.
     * 
     * @param elementOrTreePath
     *           the element
     * @param expanded
     *           <code>true</code> if the node is expanded, and <code>false</code>
     *           if collapsed
     */
    public void setExpandedState(Object elementOrTreePath, boolean expanded) {
        Assert.isNotNull(elementOrTreePath);
        Widget item = internalExpand(elementOrTreePath, false);
        if (item instanceof Item) {
            if (expanded) {
                createChildren(item);
            }
            setExpanded((Item) item, expanded);