def METHOD_NAME(self):
    N = 1000
    population = [-2, -1, 0, 1, 2]
    hist = {}
    for i in xrange(N):
        sampled = random.sample(population, 2)
        key = ','.join(str(x) for x in sampled)
        hist[key] = hist.get(key, 0) + 1
    # There are m * (m-1) ways to pick an ordered pair. The
    # observed number of occurrences of a pair follows a
    # Binomial(N, 1/(m*(m-1))) distribution.
    m = len(population)
    p = 1.0 / (m*(m-1))
    mean = N*p
    stddev = sqrt(N*p*(1-p))
    low = mean - 4*stddev
    high = mean + 4*stddev
    for a in population:
        for b in population:
            if a != b:
                key = '%s,%s' % (a, b)
                observed = hist.get(key, 0)
                self.assertLess(low, observed, 'Sample %s' % key)
                self.assertGreater(high, observed, 'Sample %s' % key)