public async Task <ActionResult <Flight> > Get([FromQuery] DateTime relative_to)
        {
            var           currTime = TimeZoneInfo.ConvertTimeToUtc(relative_to);
            List <Flight> flights;
            string        s = Request.QueryString.Value;

            if (s.Contains("sync_all"))
            {
                // Get the flights from the db and all the servers.
                flights = await model.GetAllFlights(currTime);
            }
            else
            {
                //Get the flight only from the db.
                flights = await model.GetFlights(currTime);
            }
            // There are no flights in this current time.
            if (flights == null || flights.Count == 0)
            {
                return(NoContent());
            }
            // There were problems with connecting to some of the servers.
            if (flights[0].FlightId.Equals("server"))
            {
                flights.RemoveAt(0);
                return(StatusCode(500, flights));
            }
            // There were validation problems with some of the flights.
            if (flights[0].FlightId.Equals("valid"))
            {
                flights.RemoveAt(0);
                return(BadRequest(flights));
            }
            return(Ok(flights));
        }