private static Set<Annotation> getQualifiers(AnnotatedElement... elements) {
        return Arrays.stream(elements)
                .filter(Objects::nonNull)
                .map(AnnotatedElement::getAnnotations)
                .flatMap(Arrays::stream)
                .filter(anno -> anno.annotationType().isAnnotationPresent(Qualifier.class))
                .collect(CollectionCollectors.toUnmodifiableSet());
    }
Returns the set of qualifying annotations on the given elements.
@param elements the annotated elements. Null elements are ignored.
@return the set of qualifying annotations on the given elements.
core/src/main/java/org/jdbi/v3/core/qualifier/Qualifiers.java