code: public boolean save(DataOutputStream out)
      {
          try
          {
              for (BaseNode node : child)
              {
                  if (node == null)
                  {
                      out.writeInt(0);
                  }
                  else
                  {
                      out.writeInt(1);
                      node.walkToSave(out);
                  }
              }
          }
          catch (Exception e)
          {
              logger.warning("保存到" + out + "失败" + TextUtility.exceptionToString(e));
              return false;
          }
  
          return true;
      }
docs: 保存到二进制输出流
  
  @param out
  @return