Writes data in JSON format into the task's output target.

        The data objects have the following attributes:

        * `_id` is the default Elasticsearch id field,
        * `text`: the text,
        * `date`: the day when the data was created.

def run(self):
        """
        Writes data in JSON format into the task's output target.

        The data objects have the following attributes:

        * `_id` is the default Elasticsearch id field,
        * `text`: the text,
        * `date`: the day when the data was created.

        """
        today = datetime.date.today()
        with self.output().open('w') as output:
            for i in range(5):
                output.write(json.dumps({'_id': i, 'text': 'Hi %s' % i,
                                         'date': str(today)}))
                output.write('\n')