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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 backend(self, name):
 """ Get backend class :param name: -- name of backend type :type name: str :return: class of backend :rtype: class,module,object """

        try:
            backend = self.get_backend_handler_path(name)
            if backend is None:
                raise ex.VSTUtilsException("Backend is 'None'.")  # pragma: no cover
            return self._get_baskend(backend)
        except KeyError or ImportError:
            msg = "{} ({})".format(name, self.err_message) if self.err_message else name
            raise ex.UnknownTypeException(msg)