1. The changes involve renaming the `TestData` class to `LabeledData` across multiple files. This includes updating the import statements in `__init__.py`, `cache.py`, `router.py`, `schema.py`, and `utils.py` to reflect this new class name. The `__all__` list in `__init__.py` is also updated to export `LabeledData` instead of `TestData`. This appears to be a conceptual renaming to better reflect the purpose of the data structure.
2. The modifications update all function signatures and type hints that previously used `TestData` to now use `LabeledData`. This affects several functions in `cache.py` including `_generate_run_cache`, `_eval_cache`, and `_grid_search_opt_cache`, as well as functions in `router.py` like `_generate_run_router` and `_eval_router`. The utility functions in `utils.py` are also updated to work with `LabeledData` instead of `TestData`.
3. The changes introduce a new `search_step` parameter in the router optimization logic within `router.py`, with a default value of 0.10. This parameter is passed through to the `_router_random_search` function and is used in the optimization process. The test file `test_threshold_optimizer.py` is updated to explicitly set this parameter to 0.5 when calling the optimize method, demonstrating how it can be configured for different search granularities during threshold optimization.