[Help wanted] How to properly add new Edge to GViewer programmatically

Hello! Please, tell me how to create and add new Egde to GViewer programmatically?
I can't get this working without some hacks at the moment(

new_edge = gcnew Edge(ivn1->Node, ivn2->Node, ConnectionToGraph::Connected, gv->LayoutEditor->EdgeAttr->Clone());
			new_edge->SourcePort = gcnew FloatingPort(new_edge->SourceNode->GeometryNode->BoundaryCurve, new_edge->SourceNode->GeometryNode->Center); // exception SourcePort is null in RouteEdge() without this
			new_edge->TargetPort = gcnew FloatingPort(new_edge->TargetNode->GeometryNode->BoundaryCurve, new_edge->TargetNode->GeometryNode->Center); // exception TargetPort is null in RouteEdge() without this
			IViewerEdge^ ive = gv->RouteEdge(new_edge);
			gv->AddEdge(ive, false); // fails without RouteEdge()
			gv->LayoutEditor->AttachLayoutChangeEvent(ive); // edge line is not moved together with nodes without this (why?)
			setLabelForEdge(ive, weight);

No file or test is named. Start by tracing the GViewer Edge, RouteEdge, AddEdge, and LayoutEditor APIs shown in the example, then establish the supported sequence for adding an edge and why ports and layout-change handling are required. Done means documenting a working programmatic procedure and the relevant behavior.