graph TD
A --> B
B --> C
C -->|back1| A
C -->|back2| B
---
+---+       
|   |       
| A |<--+   
|   |   |   
+---+   |   
  |     |   
  |     |   
  |     |   
  |     |   
  v     |   
+---+   |   
|   |   |   
| B |<back1 
|   |   |   
+---+   |   
  |     |   
  |     |   
  |   back2 
  |     |   
  v     |   
+---+   |   
|   |   |   
| C |---+   
|   |       
+---+       