This is a yielding function. When called, it will pause the Lua thread that called the function until a result is ready to be returned, without interrupting other scripts.
With the introduction of the update, this function became obsolete, as the Best Friends feature was removed. This method now functions identically to
Player/IsFriendsWith, and doesn’t need to be used.
The IsBestFriendsWith function returns whether a player is friends with the specified user.
Note: It was once used to return whether a player is best friends with the specified user, but the best friend feature has since been removed.