变量A变量already_migratingalready_migratingin_game/events/estates/cossacks_estate_events.txt:451变化方式来源位置变更·人民迁移到草原immediatemonths 48, 设为yes关联检查来源 1·人民迁移到草原immediate, trigger设置来源 1·人民迁移到草原immediate