startArrowheadMove, is there a document on how to use this ?

[Jay C]

I am trying to add dynamic link to existing rect's

I have left-nav with links icon and drag it to right-nav (Paper Area) on top of rect node.

Using 2 components (left-nav & paper-area) and on drop of paper-area I am able to get the rect node model using 

const elementDroppedOn = this.graph.findModelsFromPoint(coordinates);

Now I have to continue drawing link. How do I go about this ?

I looked at example from "I do not have access to the parameters of the DefaultLink : function(cellView, magnet) - Jointjs" thread.