func (c *ParHashCollector) makePartitions(sgs store.SubGraphs) (p_it partitionIterator) { keys := sgs.Keys() p_it = func() (part store.Iterator, next partitionIterator) { var key []byte key, keys = keys() if keys == nil { return nil, nil } return bufferedIterator(sgs.Find(key), 10), p_it } return p_it }