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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def list(self, per_page=None, page=None, status=None, service='facebook'):
 """ Get a list of Pylon tasks :param per_page: How many tasks to display per page :type per_page: int :param page: Which page of tasks to display :type page: int :param status: The status of the tasks to list :type page: string :param service: The PYLON service (facebook) :type service: str :return: dict of REST API output with headers attached :rtype: :class:`~datasift.request.DictResponse` :raises: :class:`~datasift.exceptions.DataSiftApiException`, :class:`requests.exceptions.HTTPError` """


        params = {}

        if per_page is not None:
            params['per_page'] = per_page
        if page is not None:
            params['page'] = page
        if status:
            params['status'] = status

        return self.request.get(service + '/task', params)