Generates :py:attr:`~.UserItemMatrix.data_size` elements.
        Writes this data in \\ separated value format into the target :py:func:`~/.UserItemMatrix.output`.

        The data has the following elements:

        * `user` is the default Elasticsearch id field,
        * `track`: the text,
        * `rating`: the day when the data was created.

def run(self):
        """
        Generates :py:attr:`~.UserItemMatrix.data_size` elements.
        Writes this data in \\ separated value format into the target :py:func:`~/.UserItemMatrix.output`.

        The data has the following elements:

        * `user` is the default Elasticsearch id field,
        * `track`: the text,
        * `rating`: the day when the data was created.

        """
        w = self.output().open('w')
        for user in range(self.data_size):
            track = int(random.random() * self.data_size)
            w.write('%d\\%d\\%f' % (user, track, 1.0))
        w.close()