+---+
          | A |
          +---+
            |
            v
+---+     +---+     +---+
| E | --> | B | <-- | G |
+---+     +---+     +---+
  ^         |         ^  
  |         v         |  
+---+     +---+     +---+
| D | <-- | C | --> | F |
+---+     +---+     +---+

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