fixed error with null resumption token
fixed error with null resumption token

jimklo/LearningRegistry,jimklo/LearningRegistry,LearningRegistry/LearningRegistry,jimklo/LearningRegistry,jimklo/LearningRegistry,LearningRegistry/LearningRegistry,jimklo/LearningRegistry,jimklo/LearningRegistry,LearningRegistry/LearningRegistry,LearningRegistry/LearningRegistry,LearningRegistry/LearningRegistry,jimklo/LearningRegistry,jimklo/LearningRegistry,LearningRegistry/LearningRegistry,jimklo/LearningRegistry,LearningRegistry/LearningRegistry