private IPolicyErrorWriter initPolicyErrorWriter() {
        Class<? extends IPolicyErrorWriter> clazz = apimanConfig.getPolicyErrorWriterClass(engine.getPluginRegistry());
        Map<String, String> conf = apimanConfig.getPolicyErrorWriterConfig();
        return ConfigDrivenEngineFactory.instantiate(clazz, conf);
    }
A base for those verticles that require an instantiated engine.

@author Marc Savy {@literal <msavy@redhat.com>}
gateway/platforms/vertx3/vertx3/src/main/java/io/apiman/gateway/platforms/vertx3/verticles/ApimanVerticleWithEngine.java