public void trace(String path,
                      String acceptType,
                      Route route,
                      ResponseTransformer transformer) {
        addRoute(HttpMethod.trace, ResponseTransformerRouteImpl.create(path, acceptType, route, transformer));
    }
Map the route for HTTP TRACE requests

@param path        the path
@param acceptType  the accept type
@param route       The route
@param transformer the response transformer
src/main/java/spark/Routable.java