docs: public void truncate(final long len) throws SQLException {
  
          final byte[] ldata = data;
  
          checkValid(ldata);
  
          if (len < 0 || len > ldata.length) {
              throw Util.outOfRangeArgument("len: " + len);
          }
  
          if (len == ldata.length) {
              return;
          }
  
          byte[] newData = new byte[(int) len];
  
          System.arraycopy(ldata, 0, newData, 0, (int) len);
          checkValid(data);    // limit possible race-condition with free()
  
          data = newData;
      }