code: public static String toPrettyJson(Object object, FieldModifier modifier) throws IllegalAccessException {
          return Formatter.formatJson(toJsonString(object, modifier));
      }
docs: 将Bean类指定修饰符的属性转换成JSON字符串
  
  @param object Bean对象
  @param modifier 属性的权限修饰符
  
  @return 格式化的JSON字符串
  
  @throws IllegalAccessException 异常