'Bring the number of pool processes up to the specified number,
for use after reaping workers which have exited.'

def _repopulate_pool(self):

    for i in range((self._processes - len(self._pool))):
        w = self.Process(target=worker, args=(self._inqueue, self._outqueue, self._initializer, self._initargs, self._maxtasksperchild))
        self._pool.append(w)
        w.name = w.name.replace('Process', 'PoolWorker')
        w.daemon = True
        w.start()
        debug('added    worker')
