TheAirline.Models.Airports.Airport.AddPassengerDestinationStatistics C# (CSharp) Method

        public void AddPassengerDestinationStatistics(Airport destination, long passengers)
        {
            lock (DestinationPassengerStatistics)
            {
                if (!DestinationPassengerStatistics.ContainsKey(destination))
                {
                    DestinationPassengerStatistics.Add(destination, passengers);
                }
                else
                {
                    DestinationPassengerStatistics[destination] += passengers;
                }
            }
        }