Merge Edeges option for layout not woking

[raibove]

I wanted to merge the edges so that they will have the same starting point. Similar to that shown in the below image

I have updated the layout and the code is available in the sandbox here
The Merge Edges property "org.eclipse.elk.layered.mergeEdges": true is not working for layout options, But the property is available in elk documentation: here

I was not able to find that property in elkLayout.ts file too.

So is it possible to merge the edges?