``` let subnodes = van.state([]); ... button({ innerHTML: '+', onclick: () => {subnodes.push(key + '.' + (subnodes.length + 1))} }), ``` if I do above, it doesn't trigger any change if I change onclick to ``` onclick: () => {subnodes.val = [...subnodes.val, (key + '.' + (subnodes.val.length + 1))]} ``` it works as expected. same issue/behavior with subnodes.val.splice any insight why push/splice doesn't work?