question: void refresh ( String filter , Set < Identity > selectedParticipants ) { Set < Identity > filteredIdentities = filter ( filter ) ; for ( Identity selectedParticipant : selectedParticipants ) { filteredIdentities . remove ( selectedParticipant ) ; } mParticipants . clear ( ) ; mParticipants . addAll ( filteredIdentities ) ; Collections . sort ( mParticipants , new IdentityDisplayNameComparator ( ) ) ; notifyDataSetChanged ( ) ; if ( mShowConversations ) { queryConversations ( selectedParticipants ) ; } }
target:  Refreshes this adapter by filtering Conversations to return only those Conversations with the given set of selected Participants.