code: public static boolean isRetainedAtRuntime(Class<? extends Annotation> annotationClass) {
          Retention retention = requireNonNull(annotationClass, "annotationClass").getAnnotation(Retention.class);
          return retention != null && RUNTIME == retention.value();
      }
docs: Returns {@code true} if the given annotation type is marked has retained at runtime.
  
  @see Retention
  @see RetentionPolicy#RUNTIME