code: public Writer setCharacterStream(long pos) throws SQLException {
      int bytePosition = utf8Position((int) pos - 1);
      OutputStream stream = setBinaryStream(bytePosition + 1);
      return new OutputStreamWriter(stream, StandardCharsets.UTF_8);
    }
docs: Set character stream.
  
  @param pos position
  @return writer
  @throws SQLException if position is invalid