@Override
    public Map<String, String> getPluginRegistryConfig() {
        Map<String, String> configMap = getConfigMap(GatewayConfigProperties.PLUGIN_REGISTRY_CLASS);
        String pluginsDirOverride = System.getProperty(GatewayConfigProperties.PLUGIN_REGISTRY_CLASS + ".pluginsDir"); //$NON-NLS-1$
        if (pluginsDirOverride != null) {
            configMap.put("pluginsDir", pluginsDirOverride); //$NON-NLS-1$
        }
        return configMap;
    }
@return all properties to be passed to the registry
gateway/platforms/war/src/main/java/io/apiman/gateway/platforms/war/WarEngineConfig.java