private void InvokeGetPurchaseConfigCallbacks(RequestCallbackState state, JsonData configJson)
 {
     if (callbacks_GetPurchaseConfig != null)
     {
         callbacks_GetPurchaseConfig.Invoke(state, configJson);
         callbacks_GetPurchaseConfig -= callbacks_GetPurchaseConfig;
     }
     isRequesting_GetPurchaseConfig = false;
 }
        public void RequestGetPurchaseConfig(RequestGetPurchaseConfigCallback callback)
        {
            callbacks_GetPurchaseConfig -= callback;
            callbacks_GetPurchaseConfig += callback;

            if (!isRequesting_GetPurchaseConfig)
            {
                isRequesting_GetPurchaseConfig = true;
                RequestGetServerData(PATH_GetPurchaseConfig, HandleGetPurchaseConfigResponse);
            }
        }