graph LR
X
subgraph one
    A --> B
end
---
        +-----------------+
        |       one       |
        |                 |
        |                 |
+---+   | +---+     +---+ |
|   |   | |   |     |   | |
| X |   | | A |---->| B | |
|   |   | |   |     |   | |
+---+   | +---+     +---+ |
        |                 |
        +-----------------+
