anchor.diff:  Future initDB(Connection conn)
   => Future.forEach(const [
     """
  -  create table "Master" (
  +  create temporary table "Master" (
       "oid" varchar(40) primary key,
       "name" varchar(60)
     )
     """, """
  -  create table "Detail" (
  +  create temporary table "Detail" (
       "oid" varchar(40) primary key,
       "createdAt" timestamp without time zone null,
       "value" integer,
  
positive.code:   })
    .whenComplete(() {
      if (conn != null) {
        return cleanDB(conn)
        .then((_) => conn.close())
        .catchError((ex, st) => print("Error ${ex.runtimeType}: $ex\n$st"));
      } else {
        print("Make sure you create a case-sensitive database called testdb, "
          "and the password must be 123");
  
negative.code:   )
    """],
    (String stmt) => conn.execute(stmt));
  