sueliangliang

Results 2 issues of sueliangliang

raise KeyError in Drain

![image](https://user-images.githubusercontent.com/50368004/149111594-103f8115-174d-4474-b139-57d8231c6bb7.png)

how to show all levels as image below

![image](https://user-images.githubusercontent.com/50368004/57300970-79e25b00-710a-11e9-8209-a7ea7daf50ee.png)