How to Properly Pass a Callback Method Reference for `Comm.makeWebRequest`

I'm trying to pass a callback method from one class to another when making a web request using `Comm.makeWebRequest`, but it doesn't seem to be working as expected.

Here's a simplified version of my setup:

class DataFetcher {
    function fetchData(url as String, callback as (Method(responseCode as Lang.Number, data as Lang.Dictionary or Lang.String or PersistedContent.Iterator or Null) as Void)) as Void {
        Comm.makeWebRequest(
            url,
            {},
            { :method => Comm.HTTP_REQUEST_METHOD_GET },
            new Lang.Method($, :callback) // Attempting to pass the callback method reference
        );
    }
}

And in another class:

class MainDelegate {
    function onSelect() {
        var fetcher = new DataFetcher();
        fetcher.fetchData("https://example.com/api", method(:handleResponse));
    }

    function handleResponse(responseCode as Lang.Number, data as Lang.Dictionary or Lang.String or PersistedContent.Iterator or Null) as Void {
        System.println("Response received: " + responseCode);
    }
}

The project builds successfully and the request is made, but when trying to invoke the callback, I get the following error:

Error: Symbol Not Found Error
Details: Failed invoking <symbol>
Stack:

What's the right way of going about this?