code: public static Class<? extends Annotation> checkIsBindingAnnotation(
        Class<? extends Annotation> annotation) {
      if (!isBindingAnnotation(annotation)) {
        throw new IllegalArgumentException(
            "Must be a binding annotation (BindingAnnotation or Qualifier)");
      }
      return annotation;
    }
docs: Returns {@code annotation} if it is a Guice binding annotation.
  
  @throws IllegalArgumentException if {@code annotation} is not a Guice binding annotation