IN CODE hint is not working

Hi, I am trying to experiment with a slightly complicated use case than what’s in the class with my own example. I have replaced the prompt questions with my own and see that the result is only “text” instead of code for the “write test cases” scenario. Enclosed is my notebook link ([https://console.cloud.google.com/vertex-ai/colab/notebooks?hl=en&project=ml-frameworks&activeNb=projects%2Fml-frameworks%2Flocations%2Fus-central1%2Frepositories%2Fe3faa045-1a08-47b9-be11-cb817310678c)](https://notebook link).

Can use some guidance.