Mysterious 'Bloc' in Testing Interface

I cannot change the content of the Testing interface. There is this mysterious 'Bloc' (without a 'k' at the end) in the interface and would like to know from where in the code this comes from. I changed the get_info() code, but it changes only what you see when the test runs, not what you see in the interface. Moreover, I looked every where in the code in my Drupal directory and there is no 'Bloc' (without a 'k') anywhere.