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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 getbyuuid(self, uuid):
 """Get a schema by given uuid. :param str uuid: schema uuid to retrieve. :rtype: Schema :raises: KeyError if uuid is not registered already. """

        if uuid not in self._schbyuuid:
            raise KeyError('uuid {0} not registered'.format(uuid))

        return self._schbyuuid[uuid]