code: private String getAnnotationValue(String annotation) {
          if (descriptor instanceof CAnnotatedDescriptor) {
              if (((CAnnotatedDescriptor) descriptor).hasAnnotation(annotation)) {
                  return ((CAnnotatedDescriptor) descriptor).getAnnotationValue(annotation);
              }
          }
          return null;
      }
docs: Get the annotation value.
  @param annotation The annotation to get.
  @return The value of the annotation, or null if not present.