erDiagram
    FlowData ||--o{ Node : contains
    FlowData ||--o{ Connection : contains
    FlowData ||--o{ Panel : contains
    FlowData ||--|| ViewState : has
    Node ||--o{ Port : has
    Connection }o--|| Port : "source port"
    Connection }o--|| Port : "target port"
    Panel }o--|| Node : "attached to"
