constructor(method, requestHeaders, request, headers, response, status, trailers) {
        this.method = method;
        this.requestHeaders = requestHeaders;
        this.request = request;
        this.headers = headers;
        this.responses = response;
        this.status = status;
        this.trailers = trailers;
    }
A server streaming RPC call. The client provides exactly one input message
but the server may respond with 0, 1, or more messages.