{
  "name": "Order",
  "fields": [
    { "name": "userId", "required": true },
    { "name": "items", "default": [] },
    { "name": "status", "default": "pending" }
  ],
  "methods": [
    {
      "name": "addItem",
      "params": ["item"],
      "body": "this.items.push(item);"
    },
    {
      "name": "removeItem",
      "params": ["productId"],
      "body": "this.items = this.items.filter(i => i.productId !== productId);"
    }
  ]
}