docs: public static Class<?> getDecoderType(Class<? extends Decoder> clazz) {
          Method[] methods = clazz.getMethods();
          for (Method m : methods) {
              if ("decode".equals(m.getName()) && !m.isBridge()) {
                  return m.getReturnType();
              }
          }
          throw JsrWebSocketMessages.MESSAGES.couldNotDetermineDecoderTypeFor(clazz);
      }