docs: private static <T, U> U convertBean(T source, Class<U> targetClass, Handler handler) {
          try {
              if (Objects.isNull(source)) {
                  return null;
              }
              return targetClass.cast(handler.getMethod().invoke(handler.getHandler(), source));
          } catch (IllegalAccessException | InvocationTargetException e) {
              throw ConvertException.of("Call method \"" + handler.getMethod() + "\" failed", e);
          }
      }