Bug 125272 [Viewers] AbstractTreeViewer needs remove(Object parentElement, Object[] childElements)
There is an add(Object parentElement, Object[] childElements) but no corresponding remove(). Without this method, if you have an element that appears under multiple parents, the only way to get model and viewer in sync after removing the element from just one of its parents is calling refresh().
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
SafeRunnable.run(new SafeRunnable() {
                public void run() {
                    l.treeCollapsed(event);
                }
            });
        }
    }
    /**
     * Fires a tree expanded event. Only listeners registered at the time this
     * method is called are notified.
     * 
     * @param event
     *           the tree expansion event
     * @see ITreeViewerListener#treeExpanded
     */
    protected void fireTreeExpanded(final TreeExpansionEvent event) {
        Object[] listeners = treeListeners.getListeners();
        for (int i = 0; i < listeners.length; ++i) {
            final ITreeViewerListener l = (ITreeViewerListener) listeners[i];
            SafeRunnable.run(new SafeRunnable() {
                public void run() {
                    l.treeExpanded(event);
                }
            });
        }
    }
    /**
     * Returns the auto-expand level.
     * 
     * @return non-negative level, or <code>ALL_LEVELS</code> if all levels