code: protected long findHighestSeqno(List<LongTuple<T>> list) {
          long seqno=-1;
          for(LongTuple<T> tuple: list) {
              long val=tuple.getVal1();
              if(val - seqno > 0)
                  seqno=val;
          }
          return seqno;
      }
docs: list must not be null or empty