code: private int getDynamicFieldSize(Object obj, Charset charset)
              throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
          int size = 0;
          for (FieldMetaData field : dynamicFieldList) {
              size = size + field.getDynamicFieldByteSize(obj, charset);
          }
          return size;
      }
docs: 获取动态数据列长度
  
  @return
  @throws NoSuchMethodException
  @throws InvocationTargetException
  @throws IllegalAccessException