if (i-1 > 0)
if (i-1 >= 0)
  Object getPreviousVisibleNode(Object node)  {    if (currentVisiblePath != null)          {        Object[] nodes = currentVisiblePath.getPath();        int i = 0;        while (i < nodes.length && !node.equals(nodes[i]))          i++;        // return the next node        if (i-1 > 0)          return nodes[i-1];      }    return null;  }