Bug 98107 [Viewers] Change visibility of AbstractTreeViewer#internalRemove from private to protected
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
/**
     * Returns the item before the given item in the tree, or <code>null</code>
     * if there is no previous item.
     * 
     * @param item
     *           the item
     * @return the previous item, or <code>null</code> if none
     */
    protected Item getPreviousItem(Item item) {
        
        
        Item parent = getParentItem(item);
        if (parent == null) {
            return null;
        }
        Item[] siblings = getItems(parent);
        if (siblings.length == 0 || siblings[0] == item) {
            return parent;
        }
        Item previous = siblings[0];
        for (int i = 1; i < siblings.length; i++) {
            if (siblings[i] == item) {
                return rightMostVisibleDescendent(previous);
            }
            previous = siblings[i];
        }
        return null;
    }
    
    protected Object[] getRawChildren(Object parent) {