graph BT
  A --> B --> C
---
+---+
|   |
| C |
|   |
+---+
  ^  
  |  
  |  
  |  
  |  
+---+
|   |
| B |
|   |
+---+
  ^  
  |  
  |  
  |  
  |  
+---+
|   |
| A |
|   |
+---+
