Render notion code block as graph by kroki
当前为 
  //kroki plantuml
  @startuml
  Alice -> "Bob()" : Hello
  "Bob()" -> "This is very\nlong" as Long
  ' You can also declare:
  ' "Bob()" -> Long as "This is very\nlong"
  Long --> "Bob()" : ok
  @enduml
PS: first line is very important