UML Class Diagram

{
  "nodes": [
    { "id":"a", "type":"class-box", "label":"Animal\n+name: string\n+age: int\n+makeSound(): void", "x":280, "y":40, "fill":"#dbeafe", "w":200, "h":140 },
    { "id":"d", "type":"class-box", "label":"Dog\n+breed: string\n+fetch(): void", "x":40, "y":260, "fill":"#dbeafe", "w":200, "h":110 },
    { "id":"c", "type":"class-box", "label":"Cat\n+indoor: bool\n+purr(): void", "x":260, "y":260, "fill":"#dbeafe", "w":200, "h":110 },
    { "id":"t", "type":"class-box", "label":"Trainer\n+name: string\n+train(a: Animal): bool", "x":520, "y":260, "fill":"#fef3c7", "w":220, "h":110 }
  ],
  "edges": [
    { "id":"e1","source":"d","target":"a","label":"inherits","style":"dashed" },
    { "id":"e2","source":"c","target":"a","label":"inherits","style":"dashed" },
    { "id":"e3","source":"t","target":"a","label":"trains 1..*" }
  ]
}