code: protected void setTupleValue(Tuple pair, int position, Object value) throws ExecException
      {
         if (value instanceof BigInteger)
             pair.set(position, ((BigInteger) value).intValue());
         else if (value instanceof ByteBuffer)
             pair.set(position, new DataByteArray(ByteBufferUtil.getArray((ByteBuffer) value)));
         else if (value instanceof UUID)
             pair.set(position, new DataByteArray(UUIDGen.decompose((java.util.UUID) value)));
         else if (value instanceof Date)
             pair.set(position, TimestampType.instance.decompose((Date) value).getLong());
         else
             pair.set(position, value);
      }
docs: set the value to the position of the tuple