Custom message of "mouse over field" for Flow Map Viz

[asandaq]

I want to change the tooltip text when hovering over a Flow Map Viz node.

I am using the event below but it does not seem to work.

var flowMapViz = mvc.Components.get('my_flow_map');
flowMapViz.$el.find('.node').on('mouseover', function(event) {
            console.log("on mouseover")
 });