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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_notes(self, page=0, since=None):
 """ Get the notes of current object :param page: the page starting at 0 :type since: int :param since: get all notes since a datetime :type since: datetime.datetime :return: the notes :rtype: list """

        from highton.models.note import Note
        params = {'n': int(page) * self.NOTES_OFFSET}
        if since:
            params['since'] = since.strftime(self.COLLECTION_DATETIME)

        return fields.ListField(
            name=self.ENDPOINT,
            init_class=Note
        ).decode(
            self.element_from_string(
                self._get_request(
                    endpoint=self.ENDPOINT + '/' + str(self.id) + '/' + Note.ENDPOINT,
                    params=params
                ).text
            )
        )