Adjust viewport metrics after view item removed

If I remove the first item from model, there is an empty space in listview before the beggining of the first item. For example:

myListView.model.remove(0); // let us have some fun
myListView.viewportY = 0; // there is an empty space!!
myListView.positionViewAtIndex(0); // all are ok, but
console.log(myListView.atYBeginning); // dumps false, but correct value is true