{
  "openapi": "3.0.4",
  "info": {
    "title": "OpenAPI 3.0.4 additional properties undefined example",
    "version": "1"
  },
  "components": {
    "schemas": {
      "Foo": {
        "properties": {
          "foo": {
            "type": "object"
          }
        },
        "required": ["foo"],
        "type": "object"
      }
    }
  }
}