{
  "worlds": [],
  "interfaces": [
    {
      "name": "x",
      "types": {},
      "functions": {},
      "package": 0
    }
  ],
  "types": [],
  "packages": [
    {
      "name": "a:b",
      "interfaces": {
        "x": 0
      },
      "worlds": {}
    }
  ]
}