+---+     +---+
| A | --> | B | <----\
+---+     +---+       |
  |         |         |
  v         v         |
+---+     +---+     +---+
| H |     | C | --> | D |
+---+     +---+     +---+
  |                   |
  v                   |
+---+                 |
| E | <----\          |
+---+       |         |
  |         |         |
  v         |         |
+---+     +---+       |
| F | --> | G | <----/
+---+     +---+

Cycles:
B -> C -> D -> B
E -> F -> G -> E