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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 cache_key_exist(self, key):
 """Returns if a key from cache exist"""

        key_exist = True if cache.get(key) else False
        status = 200 if key_exist else 404
        return json_success(json.dumps({'key_exist': key_exist}),
                            status=status)