/**
     * load the widgets from a list. This will call update() on each (matching by id) or add/remove widgets that are not there.
     *
     * @param layout list of widgets definition to update/create
     * @param addAndRemove boolean (default true) or callback method can be passed to control if and how missing widgets can be added/removed, giving
     * the user control of insertion.
     *
     * @example
     * see http://gridstackjs.com/demo/serialization.html
     */
    load(items: GridStackWidget[], addRemove?: boolean | AddRemoveFcn): GridStack;