def _walk_subclasses(klass):
    for sub in klass.__subclasses__():
        yield sub
        for subsub in _walk_subclasses(sub):
            yield subsub


# Build the code->exception class mapping.
deviance defined as 2 times the negative loglikelihood
dataset/ETHPy150Open GoogleCloudPlatform/gcloud-python/gcloud/exceptions.py/_walk_subclasses--crossover with--dataset/ETHPy150Open statsmodels/statsmodels/statsmodels/sandbox/panel/mixed.py/OneWayMixed.deviance