presto-raptor-legacy/src/main/java/io/prestosql/plugin/raptor/legacy/metadata/ShardNodes.java/ShardNodes/ShardNodes
class ShardNodes:    public ShardNodes(UUID shardUuid, Set<String> nodeIdentifiers)
    {
        this.shardUuid = requireNonNull(shardUuid, "shardUuid is null");
        this.nodeIdentifiers = ImmutableSet.copyOf(requireNonNull(nodeIdentifiers, "nodeIdentifiers is null"));
    }