I’m writing a ServerInterceptor that might respond with a predefined response. In order to construct a response, I need a builder of that type but I can’t find a way to get it.

Here is the declaration of the method:

@Override
public <ReqT, RespT> ServerCall.Listener<ReqT> interceptCall(
    ServerCall<ReqT, RespT> call,
    Metadata headers,
    ServerCallHandler<ReqT, RespT> next) {

    // how to get a builder of RespT here?
    ...
}

I found out that there is call.getMethodDescriptor().getResponseMarshaller() method and if I cast it to ReflectableMarshaller<RespT>, I can invoke getMessageClass() to get Class for a response. But how I can get a builder for that class then?