public ImportThread(RuntimeTerrainImporter runOn, Func <T> toRun, Action <T> callback)
        {
            this.runOn    = runOn;
            this.toRun    = toRun;
            this.callback = callback;

            runOn.StartCoroutine(CheckIfDone());
        }
        public static void StartThread <T>(RuntimeTerrainImporter runOn, Func <T> toRun, Action <T> callback)
        {
            var importThread = new ImportThread <T>(runOn, toRun, callback);

            (new Thread(importThread.Start)).Start();
        }