public static void RenameRank( Rank rank, string newName ) { if( rank == null ) throw new ArgumentNullException( "rank" ); if( newName == null ) throw new ArgumentNullException( "newName" ); RanksByName.Remove( rank.Name.ToLower() ); rank.Name = newName; RanksByName.Add( rank.Name.ToLower(), rank ); }