function MyGroup() {
go.Group.apply(this,arguments);
};
go.Diagram.inherit(MyGroup, go.Group);
Then the drag functionality seems to go wrong. If I attempt to drag a group, the contained nodes move but not the containing group. All other functionality seems to be okay (select, resize etc).
I’m sorry. At the current time you cannot subclass any GraphObject, including Group.
It is unfortunate that there is such limited support for “classes” in JavaScript.
That is why we have added a bunch of properties whose values are functions (not “methods”).
Those functional properties greatly help reduce the need for subclassing.