Freeze due to stack overflow

[codefrau]

I got a "Maximum call stack size exceeded" exception in

get(e)
{
    var i;
    if (this.writes.has(e))
        return this.writes.get(e);
    let t = this.parentValueCache.deref();
    if (t != null && t.has(e))
        return this.parentValueCache.deref().get(e);
    const r = (i = this.parent) == null ? void 0 : i.get(e);     // <== Maximum call stack size exceeded
    return t || (t = new WeakMap, this.parentValueCache = new WeakRef(t)), t.set(e, r), r
}