static/ext/src/selection/Model.js
function(fireEvent) {
        var me = this;
        if (fireEvent && !me.bulkChange) {
            me.fireEvent('selectionchange', me, me.getSelection());
        }
    }
function(fireEvent) {
        var me = this;
        if (fireEvent && !me.bulkChange) {
            me.fireEvent('selectionchange', me, me.getSelection());
        }
    }
fire selection change as long as true is not passed into maybeFireSelectionChange