Keys must be unique throughout the UltraTree control.
Any node with a key can be referenced anywhere in the UltraTree control by calling the UltraTree.GetNodeByKey method.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2