public ActionResult <string> Post([FromBody] FlightPlan flightPlan) { if (flightManager.IsSegmentsValid(flightPlan) == false) { return(BadRequest("Invalid flightplan location")); } string flightPlanId = flightManager.CreateIdentifier(flightPlan); flightPlan.FlightPlanId = flightPlanId; memoryCache.Set(flightPlan.FlightPlanId, flightPlan); List <string> fpKeys = new List <string>(); if (!memoryCache.TryGetValue("flightListKeys", out fpKeys)) { fpKeys = new List <string>(); fpKeys.Add(flightPlan.FlightPlanId); memoryCache.Set("flightListKeys", fpKeys); } else { fpKeys.Add(flightPlan.FlightPlanId); } return(Ok(flightPlanId)); }