jQuery sortable fix scrolling top when on the bottom of a page

gistfile1.js

$(".layers-container").sortable({
    placeholder: "layer-empty",
    containment: "parent",
    tolerance: "pointer",
    cursor: "grabbing",
})
.disableSelection();

var instance = $(".layers-container").data("ui-sortable");
instance.__createHelper = instance._createHelper;
instance._createHelper = function(event) {
    this.scrollTop = this.element.scrollParent().scrollTop();
    console.log("_createHelper", this.element.scrollParent()[0], this.scrollTop);
    return this.__createHelper(event);
};
instance.__createPlaceholder = instance._createPlaceholder;
instance._createPlaceholder = function() {
    this.__createPlaceholder();
    console.log("_createPlaceholder", this.element.scrollParent()[0], this.scrollTop);
    this.element.scrollParent().scrollTop(this.scrollTop);
};