One reason to override this method would be to take advantage of added functionality of sub-classes of IGoLink, for example, a sub-class that tracked bend points and allowed them to be repositioned by the application. See also LayoutNodes and LayoutLinks. Although this method does not start or finish an undo manager transaction, it is compliant with undo and redo by calling Northwoods.Go.GoDocument.RaiseChanging and Northwoods.Go.GoDocument.RaiseChanged with a hint of Northwoods.Go.GoDocument.AllArranged. This also updates the Document's Northwoods.Go.GoDocument.TopLeft and Northwoods.Go.GoDocument.Size properties to account for objects that have moved and potentially increased the extent of the document.

Reference

GoLayoutLayeredDigraph Class
GoLayoutLayeredDigraph Members