'Train Bayes by telling him that item belongs
in pool. uid is optional and may be used to uniquely
identify the item that is being trained on.'

def train(self, pool, item, uid=None):

    tokens = self.getTokens(item)
    pool = self.pools.setdefault(pool, self.dataClass(pool))
    self._train(pool, tokens)
    self.corpus.trainCount += 1
    pool.trainCount += 1
    if uid:
        pool.training.append(uid)
    self.dirty = True
