The important idea behing the exporter project is to avoid buffering data on the PHP side to avoid large memory usage. The current code cannot be used with a large file as all the lines are stored in the ``$this->lines`` array.

The ``next()`` function must have the ``fgetcsv($this->file, 0, $this->delimiter, $this->enclosure, $this->escape)`` call, and you need to set a property ``$currentLine`` which contains the current line (read by ``next()``)