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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_token(self):
 """ Method to retrieve an auth token. The cached global token is looked up and returned if it exists. If it is `None` a new one is requested and returned. Returns: Simplenote API token as string """

        if self.token == None:
            self.token = self.authenticate(self.username, self.password)
        try:
            return str(self.token,'utf-8')
        except TypeError:
            return self.token