@SuppressWarnings("unchecked")
    private static <T> Constructor<T> getConstructor(Class<T> builderClass) {
        Constructor<?>[] constructors = builderClass.getConstructors();
        assert(constructors.length == 1);
        return (Constructor<T>) constructors[0];
    }
Utility class for instantiating a builder using reflection.

@author Tony Vaagenes
config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/chains/DomBuilderCreator.java