'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'

def _job_sorting_key(self, job):

    if (self._base_graph is None):
        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)
