type linear_unit_info = {mutable unit_name : string;mutable items : linear_item_info list;mutable for_pack : string option;
}val save : string -> linear_unit_info -> unitval restore : string -> linear_unit_info * Digest.ttype linear_unit_info = {mutable unit_name : string;mutable items : linear_item_info list;mutable for_pack : string option;}val save : string -> linear_unit_info -> unitval restore : string -> linear_unit_info * Digest.t