code: public static Object getDefaultValue(Annotation annotation, String attributeName) {
          return getDefaultValue(annotation.annotationType(), attributeName);
      }
docs: Retrieve the <em>default value</em> of a named Annotation attribute, given an annotation instance.
  @param annotation the annotation instance from which to retrieve the default value
  @param attributeName the name of the attribute value to retrieve
  @return the default value of the named attribute, or <code>null</code> if not found
  @see #getDefaultValue(Class, String)