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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 load_all(self, keys=None, replace_existing_values=True):
 """ Loads all keys from the store at server side or loads the given keys if provided. :param keys: (Collection), keys of the entry values to load (optional). :param replace_existing_values: (bool), whether the existing values will be replaced or not with those loaded from the server side MapLoader (optional). """

        if keys:
            key_data_list = list(map(self._to_data, keys))
            return self._load_all_internal(key_data_list, replace_existing_values)
        else:
            return self._encode_invoke(map_load_all_codec, replace_existing_values=replace_existing_values)