graph LR
subgraph one
    A -->|sends| B
end
subgraph two
    C -->|receives| D
end
B -->|data| C
---
+-------------------+  +----------------------+
|        one        |  |         two          |
|                   |  |                      |
|                   |  |                      |
| +---+       +---+ |  | +---+          +---+ |
| |   |       |   | |  | |   |          |   | |
| | A |-sends>| B |data->| C |receives->| D | |
| |   |       |   | |  | |   |          |   | |
| +---+       +---+ |  | +---+          +---+ |
|                   |  |                      |
+-------------------+  +----------------------+
