protected IAsyncResultHandler<Void> getResultHandler() {
        return handler;
    }
Creates a new instance of the given type, passing the given config
map if possible (if the class has a Map constructor).
@param type the type to create
@param config config to pass
@return a new instance of 'type'
gateway/engine/core/src/main/java/io/apiman/gateway/engine/impl/ConfigDrivenEngineFactory.java