TreeNode getPreviousNode(TreeNode node)
Object getPreviousNode(Object node)
  TreeNode getPreviousNode(TreeNode node)  {    TreeNode parent = node.getParent();    if (parent == null)      return null;        TreeNode sibling = getPreviousSibling(node);    if (sibling == null)      return parent;    int size = sibling.getChildCount();    while (size > 0)    {      sibling = sibling.getChildAt(size - 1);      size = sibling.getChildCount();    }          return sibling;  }