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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 _clean_ctx(self):
 """ Cleans up cipher ctx and deallocates it """

        try:
            if self.ctx is not None:
                self.__ctxcleanup(self.ctx)
                libcrypto.EVP_CIPHER_CTX_free(self.ctx)
                del self.ctx
        except AttributeError:
            pass
        self.cipher_finalized = True