{
  "id": "Extension.json",
  "type": "object",
  "datatype": true,
  "category": "fhir",
  "properties": {
    "url": {
      "type": "string",
      "format": "url"
    },
    "valueElement": {
      "$ref": "Element.json"
    }
  },
  "additionalProperties": false,
  "required": [
    "url"
  ]
}