1. In test mode, this function deletes the internal working directory. It is recommended to call this function at the beginning of a test, such that the test does not load data from the working directory of a previous test run.

2. If the working directory does not exist, the function returns immediately. If the working directory cannot be deleted, e.g., because another application has a lock on a file, the function raises an exception.

3. Setting this property when insight.test_mode is False will cause the model to abort with a runtime error.