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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 exists(self, key, **opts):
 """Return if a key exists in the cache."""

        key, store = self._expand_opts(key, opts)
        data = store.get(key)
        # Note that we do not actually delete the thing here as the max_age
        # just for this call may have triggered a False.
        if not data or self._has_expired(data, opts):
            return False
        return True