code: @Override
      public void write(Object key, List<ByteBuffer> values) throws IOException
      {
          prepareWriter();
          try
          {
              ((CQLSSTableWriter) writer).rawAddRow(values);
              
              if (null != progress)
                  progress.progress();
              if (null != context)
                  HadoopCompat.progress(context);
          } 
          catch (InvalidRequestException e)
          {
              throw new IOException("Error adding row with key: " + key, e);
          }
      }
docs: The column values must correspond to the order in which
  they appear in the insert stored procedure.
  
  Key is not used, so it can be null or any object.
  </p>
  
  @param key
  any object or null.
  @param values
  the values to write.
  @throws IOException