src/main/java/javascalautils/concurrent/FutureImpl.java
@Override
    public void onFailure(Consumer<Throwable> consumer) {
        Validator.requireNonNull(consumer, "Null is not a valid consumer");
        // register a complete handler and ignore any Success responses
        onComplete(result -> {
            // transform Failure to a Success with the Throwable
            // should it be a Success it will be transformed into a Failure and forEach will do nothing
            result.failed().forEach(consumer);
        });
    }
@Override
    public void onFailure(Consumer<Throwable> consumer) {
        Validator.requireNonNull(consumer, "Null is not a valid consumer");
        // register a complete handler and ignore any Success responses
        onComplete(result -> {
            // transform Failure to a Success with the Throwable
            // should it be a Success it will be transformed into a Failure and forEach will do nothing
            result.failed().forEach(consumer);
        });
    }
/*
(non-Javadoc)

@see javascalautils.concurrent.Future#onFailure(java.util.function.Consumer)