# ServiceExtensionHandler typedef

Future<ServiceExtensionResponse> ServiceExtensionHandler (String method, Map<String, String> parameters)

A service protocol extension handler. Registered with `registerExtension`.

Must complete to a `ServiceExtensionResponse`. `method` is the method name of the service protocol request, and `parameters` is a map holding the parameters to the service protocol request.

NOTE: all parameter names and values are encoded as strings.