code: def _job_sorting_key(self, job):
          
  
          if self._base_graph is None:
              # we don't do sorting if there is no base_graph
              return 0
  
          MAX_JOBS = 1000000
  
          if job.addr not in self._node_addr_visiting_order:
              return MAX_JOBS
  
          return self._node_addr_visiting_order.index(job.addr)
docs: Get the sorting key of a CFGJob instance.
  
          :param CFGJob job: the CFGJob object.
          :return: An integer that determines the order of this job in the queue.
          :rtype: int