Computed array subscription arrayChange

JavaScript

var Class1 = function constructor(something) {
    this.something = something;
};

var baseArray = ko.observableArray();

var computedTest = ko.computed(function() {  
    return ko.utils.arrayFilter(baseArray(), function (item) {
        return item.something !== undefined;
    });
}).extend({trackArrayChanges:true});

console.clear();


// COMPUTED

computedTest.subscribe(function(){
    console.log('COMPUTED subscription : classic');
});
// The following does not work, but I'd like it
computedTest.subscribe(function(changesList){
    console.log(changesList);
}, null, 'arrayChange');

baseArray.push(new Class1('x'))