partyGuestCount() could be an awesome function!

[lcivita]

Is your feature request related to a problem? Please describe.
Not an unsolvable problem, but a quality of life one. Currently the only way to see the amount of guests online is by having them each create their own shared object, and then checking the length of that array.

Describe the solution you'd like
An easier way of accessing this, built into the library.

Describe alternatives you've considered
A function returning an int partyGuestCount().

Additional context
It's not a huge deal! Could just make a few things easier given that I find myself often wanting to use this function.