@SuppressWarnings("unchecked")
    private List<Class<ConfigInstance>> configParameterClasses() {
        List<Class<ConfigInstance>> ret = new ArrayList<>();
        for (Type type : constructor.getGenericParameterTypes()) {
            if (type instanceof Class && ConfigInstance.class.isAssignableFrom((Class<?>) type)) {
                ret.add((Class<ConfigInstance>) type);
            }
        }
        return ret;
    }
@author Tony Vaagenes
@author gjoranv
@author ollivir
container-core/src/main/java/com/yahoo/container/di/componentgraph/core/ComponentNode.java