+---+   +---+
        |   |   |   |
        +-+-+   +-+-+
          |       |
          |       |
        +-v-+   +-v-+
        |   |   |   |
        +-+-+   +-+-+
          |       |
          |       |
+---+   +-v-+     |
|   |   |   <-----+
+-+-+   +-+-+
  |       |
  |       |
  |     +-v-+
  +----->   |
        +-+-+
          |
          |
        +-v-+
        |   |
        +---+