Detecting changes in observable subscribers

[DanielMcCrystal]

Is there any way to create a Property that represents the current set of subscribers on a given observable?

For example:

const obs = Kefir.fromPoll(100, () => "anything");
const obsSubscribers = obs.subscribers(); // << imaginary function
obsSubscribers.log();

setTimeout(() => {
    const fn = () => {...}
    const first = obs.onAny(fn);
    setTimeout(() => obs.offAny(fn), 2000)
}, 1000);
setTimeout(() => {
    const second = obs.onAny(...);
}, 2000);

s[0]----s[1]----s[2]----s[3]---
================
s[0] = [] << obs does not have any subscribers
s[1] = [first]
s[2] = [first, second]
s[3] = [second]

Or maybe just a boolean property that tracks whether or not the observable is active?