def METHOD_NAME(config, tests_root_dir):
    """Check that all the tests declared in the config file correspond to actual valid test functions"""
    logging.info("Checking that configured tests exist")
    test_functions = discover_all_test_functions(tests_root_dir)
    unused_test_functions = deepcopy(test_functions)
    try:
        with soft_assertions():
            for dirname, configured_tests in config["test-suites"].items():
                assert_that(test_functions).contains_key(dirname)
                assert_that(test_functions.get(dirname, [])).contains(*[test for test in configured_tests.keys()])
                unused_test_functions[dirname] = list(unused_test_functions[dirname] - configured_tests.keys())
    except AssertionError as e:
        logging.error("Some of the configured tests do not exist: %s", e)
        raise
    logging.info("Found following unused test functions: %s", json.dumps(unused_test_functions, indent=2))