How to add a single friend or remove a single friend

Hi guys,

I use Photon Chat. I use chatClient.AddFriends( friendNamesArray ) to add the list of friends for which I want to get the online status. I have a feature that allows you to add a friend (or remove a friend). The friend list is stored by the app. Is there a way I can add a single friend to Photon or do I need to:

chatClient.RemoveFriends( oldFriendNamesArray ) and then do chatClient.AddFriends( newFriendNamesArrayWithOneMoreFriend ) or will photon add the diff between the first list and the new list by just calling chatClient.AddFriends( newFriendNamesArrayWithOneMoreFriend )?

Thanks,