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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 make_cache(self, backend=None):
 """Make a cache to reduce the time of run. Some backends may implemented it. This is temporary API. It may changed or deprecated."""

        if backend is None:
            if self._default_backend is None:
                backend = DEFAULT_BACKEND_NAME
            else:
                backend = self._default_backend
        return self.__get_backend(backend).make_cache(self.ops, self.n_qubits)