code: public void encode(DerOutputStream out) throws IOException {
          DerOutputStream seq = new DerOutputStream();
  
          for (int i = 0, n = size(); i < n; i++) {
              get(i).encode(seq);
          }
          out.write(DerValue.tag_Sequence, seq);
      }
docs: Encode the GeneralSubtrees.
  
  @params out the DerOutputStrean to encode this object to.