UFT Pro (LeanFT) .NET SDK Reference, Version 14.03
EnableLabelEditing Method (ITreeViewNode)
Activates the edit mode for this node in the tree-view control to enable renaming.

IMPORTANT: This method only enables the node for renaming. To actually rename the node, you must set its value using the IEditField or IEditor test object, together with an applicable method.
void EnableLabelEditing()