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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 get_published_or_draft(self):
 """ Return the published item, if it exists, otherwise, for privileged users, return the draft version. """

        if self.is_published:
            return self
        elif self.publishing_linked_id:
            return self.publishing_linked
        if is_draft_request_context():
            return self.get_draft()
        # There is no public version, and there is no privilege to view the
        # draft version
        return None