Status: IN
Some solution files (e.g., `count-prefixes-of-a-given-string/solution.py`) contain both the algorithm and a `unittest`-based test class in the same file, with a `__main__` guard for direct execution, rather than using a separate `test_solution.py`.
Source: entries/2026/06/06/count-prefixes-of-a-given-string-solution.md