docs: public void loadThruStagePipes(Reader reader) throws Exception {
          SeriesPipes p = (SeriesPipes) pipes;
          // 通过迭代加入样本
          Pipe p1 = p.getPipe(0);
          while (reader.hasNext()) {
              Instance inst = reader.next();
              if(inst!=null){
                  if (p1 != null)
                      p1.addThruPipe(inst);
                  this.add(inst);
                 
              };
          }
          for (int i = 1; i < p.size(); i++)
              p.getPipe(i).process(this);
      }