Simple diagram
.
```plantuml
@startuml
Bob -> Alice : hello
@enduml
```
.
<img src="https://www.plantuml.com/plantuml/svg/SoWkIImgAStDuNA0ivpoanHqxHGSSpAJKnMi539IStBokHnIyrB0oY0q0000" alt="uml diagram">
.