def __init__(self, cond_samples=None):
        defaultdict.__init__(self, FreqDist)
        if cond_samples:
            for (cond, sample) in cond_samples:
                self[cond][sample] += 1
Group tests together based on their results.
dataset/ETHPy150Open nltk/nltk/nltk/probability.py/ConditionalFreqDist.__init__--crossover with--dataset/ETHPy150Open twisted/twisted/twisted/trial/reporter.py/Reporter._groupResults