pub fn run_server<SocketAddress, Engine>(
    shared_content_engine: Arc<RwLock<Engine>>,
    index_route: Option<Route>,
    error_handler_route: Option<Route>,
    socket_address: SocketAddress
) -> Result<(), Error> where
    SocketAddress: 'static + ToSocketAddrs,
    Engine: 'static + ContentEngine<ServerInfo> + Send + Sync