public DBManager(){
mainDB = new MainDB ();
supervillainsDB = new SupervillainsDB ();
schoolClassDB = new SchoolClassDB ();
buildingDB = new BuildingDB (schoolClassDB);
researchDB = new ResearchDB ();
superHeroesDB = new SuperheroesDB ();
superPowersDB = new SuperPowersDB();
eventDB = new EventDB();
}
