Check if Image is defined in IonResource retry callback
Check if Image is defined in IonResource retry callback

CesiumGS/cesium,CesiumGS/cesium,CesiumGS/cesium,likangning93/cesium,CesiumGS/cesium,AnalyticalGraphicsInc/cesium,AnalyticalGraphicsInc/cesium,likangning93/cesium,CesiumGS/cesium,likangning93/cesium,likangning93/cesium,likangning93/cesium