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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 invalidate(self, key, **kw):
 """Invalidate a value in the cache. :param key: the value's key. :param \**kw: cache configuration arguments. The backend is configured using these arguments upon first request. Subsequent requests that use the same series of configuration values will use that same backend. """

        self.impl.invalidate(key, **self._get_cache_kw(kw, None))