code: private static Set<Annotation> getQualifiers(Injectee injectee) {
      // JSR 330's @Qualifier
      Set<Annotation> qualifiers = injectee.getRequiredQualifiers();
      if (!qualifiers.isEmpty()) {
        return qualifiers;
      }
      
      AnnotatedElement element = injectee.getParent();
      int position = injectee.getPosition();
      
      // Guice's @BindingAnnotation is the same as @Qualifier
      Annotation annotation = getBindingAnnotation(element, position);
      if (annotation != null) {
        return Collections.singleton(annotation);
      }
      
      return Collections.emptySet();
    }
docs: NOTE: There can be only one {@link Annotation} that is a {@link Qualifier} or {@link BindingAnnotation}.
  They're the same but HK2 does not know about {@link BindingAnnotation}.
  
  @see Qualifier
  @see BindingAnnotation
  @see javax.inject.Named
  @see com.google.inject.name.Named