实现告警四态状态机

solve()

Alarm state machine:
  ALM001 (DEV004): state=closed, next=[]
  ALM002 (DEV008): state=acknowledged, next=['resolving']
  ALM003 (DEV001): state=resolving, next=['closed']
  ALM004 (DEV009): state=triggered, next=['acknowledged']
  ALM005 (DEV007): state=closed, next=[]
Pending acknowledgement: 1