get_shard_names returns an array containing the names of the shards
        in the cluster. This is determined with num_shards and
        shard_name_format

def get_shard_names(self):
        """
        get_shard_names returns an array containing the names of the shards
        in the cluster. This is determined with num_shards and
        shard_name_format
        """
        results = []
        for shard_num in range(0, self.num_shards()):
            shard_name = self.get_shard_name(shard_num)
            results.append(shard_name)

        return results