def _push(self, job, flush=False, block=True):
        self.last_job = job
        self.last_job_push = time.time()
        # get client local job id to map current difficulty
        self.job_counter += 1
        if self.job_counter % 100 == 0:
            # Run a swap to avoid GC
            tmp = self.job_mapper
            self.old_job_mapper = self.job_mapper
            self.job_mapper = tmp
            self.job_mapper.clear()
        job_id = str(self.job_counter)
        self.job_mapper[job_id] = (self.difficulty, weakref.ref(job))
        self.write_queue.put(job.stratum_string() % (job_id, "true" if flush else "false"), block=block)
List the n most common elements and their counts from the most
dataset/ETHPy150Open simplecrypto/powerpool/powerpool/stratum_server.py/StratumClient._push--crossover with--dataset/ETHPy150Open Exa-Networks/exabgp/lib/exabgp/dep/counter.py/Counter.most_common