linkFunction method
Links a function controller to the receiver to form a request channel.
If the receiver does not respond to a request, handle
receives the request next.
See link for a variant of this method that takes an object instead of a closure.
Implementation
@override
Linkable? linkFunction(
FutureOr<RequestOrResponse?> Function(Request request) handle,
) {
return _nextController = _FunctionController(handle);
}