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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_task_cls(cls, name):
 """ Returns an unambiguous class or raises an exception. """

        task_cls = cls._get_reg().get(name)
        if not task_cls:
            raise TaskClassNotFoundException(cls._missing_task_msg(name))

        if task_cls == cls.AMBIGUOUS_CLASS:
            raise TaskClassAmbigiousException('Task %r is ambiguous' % name)
        return task_cls