Two-name injection: function ($id, $response). The framework injects $id from the URL and $response from the framework. Note the custom X-Demo-Injected header on this very response.
GET /demo/inject/url-response/42 {
"id": "42",
"injected": [
"id",
"response"
],
"header_set": "X-Demo-Injected: id+response"
}