code: @SuppressWarnings("unchecked")
      public final List<String> getAudienceAsList() {
          if (audience == null) {
              return Collections.emptyList();
          }
          if (audience instanceof String) {
              return Collections.singletonList((String) audience);
          }
          return (List<String>) audience;
      }
docs: Returns the list of audience claim that identifies the audience that the JWT is intended for
  or empty for none.