javascript – How to open the information bubble in the hover

I have problems to come up with a solution to the problem raised.
It seems that there is another way to add an event detector to the marker than the one proposed here in the official example.

The annoying piece of code in question:

                group.addEventListener (& # 39; mouseover & # 39 ;, function (evt) {
// the objective of the event is the marker itself, the group is the main event objective
// for all the objects it contains
console.log (`Is it already working?`)
var bubble = new H.ui.InfoBubble ( (), {
// read custom data
content: ()
// shows the information bubble
ui.addBubble (bubble);
}, false);