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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 clear_authentication(self):
 """Clear any existing authentication on the reddit object. This function is implicitly called on `login` and `set_access_credentials`. """

        self._authentication = None
        self.access_token = None
        self.refresh_token = None
        self.http.cookies.clear()
        self.user = None