// Returns the total number of currently active authoritative matches.
Count()int
// Pass a user join attempt to a match handler. Returns if the match was found, if the join was accepted, a reason for any rejection, and the match label.
// Pass a user join attempt to a match handler. Returns if the match was found, if the join was accepted, if it's a new user for this match, a reason for any rejection, the match label, and the list of existing match participants.