JSFiddle - React, Tailwind, and code Playground
HTML
<iframe>
</iframe>
JavaScript
console.log(Array.prototype.slice.call(top.frames), Array.prototype.slice.call(this.frames))
this.frames[0].x = 1;
console.log(top.x, this.frames[0].x)
<iframe>
</iframe>
console.log(Array.prototype.slice.call(top.frames), Array.prototype.slice.call(this.frames))
this.frames[0].x = 1;
console.log(top.x, this.frames[0].x)