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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 _bulk_cache_lookup(self, api_name, keys):
 """Performes a bulk cache lookup and returns a tuple with the results found and the keys missing in the cache. If cached is not configured it will return an empty dictionary of found results and the initial list of keys. Args: api_name: a string name of the API. keys: an enumerable of string keys. Returns: A tuple: (responses found, missing keys). """

        if self._cache:
            responses = self._cache.bulk_lookup(api_name, keys)
            missing_keys = [key for key in keys if key not in responses.keys()]
            return (responses, missing_keys)

        return ({}, keys)