print the number of work units in an existing work spec

def do_status(self, args):
        '''print the number of work units in an existing work spec'''
        work_spec_name = self._get_work_spec_name(args)
        status = self.task_master.status(work_spec_name)
        self.stdout.write(json.dumps(status, indent=4, sort_keys=True) +
                          '\n')