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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_objective_bank(self):
 """Gets the ObjectiveBank associated with this session. return: (osid.learning.ObjectiveBank) - the ObjectiveBank associated with this session raise: OperationFailed - unable to complete request raise: PermissionDenied - authorization failure compliance: mandatory - This method must be implemented. """

        # This should probably be accomplished via a handcar call instead of OSID
        url_path = construct_url('objective_banks',
                                 bank_id=self._catalog_idstr)
        return objects.ObjectiveBank(self._get_request(url_path))