docs: private static byte[] convertFieldToByte(ObjectMetaData objectMap, Object object, Charset charset)
              throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
          List<FieldMetaData> mappingFields = objectMap.getFieldList();
          // 获取报文长度 (固定长度+动态长度)
          int size = objectMap.getFieldsSendTotalByteSize(object, charset);
          byte[] result = new byte[size];
          int offsize = 0;
          for (int i = 0; i < mappingFields.size(); i++) {
              FieldMetaData field = mappingFields.get(i);
              byte[] fieldByte = field.toByte(object, charset);
              if (null != fieldByte) {
                  System.arraycopy(fieldByte, 0, result, offsize, fieldByte.length);
                  offsize += fieldByte.length;
              }
          }
          return result;
      }