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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_learning_path_session_for_objective_bank(self, objective_bank_id=None):
 """Gets the OsidSession associated with the learning path service for the given objective bank. arg: objectiveBankId (osid.id.Id):
 the Id of the ObjectiveBank return: (osid.learning.LearningPathSession) - a LearningPathSession raise: NotFound - no objective bank found by the given Id raise: NullArgument - objectiveBankId is null raise: OperationFailed - unable to complete request raise: Unimplemented - supporty_learning_path() or supports_visible_federation() is false compliance: optional - This method must be implemented if supports_learning_path() and supports_visible_federation() are true """

        if not objective_bank_id:
            raise NullArgument
        if not self.supports_learning_path():
            raise Unimplemented()
        try:
            from . import sessions
        except ImportError:
            raise OperationFailed()
        try:
            session = sessions.LearningPathSession(objective_bank_id, runtime=self._runtime)
        except AttributeError:
            raise OperationFailed()
        return session