@Test public void getFirst() { assertThat(factory.create(1)).isNotNull(); }
public abstract Level create(int level);
LevelFactory { public abstract Level create(int level); }
LevelFactory { public abstract Level create(int level);  }
LevelFactory { public abstract Level create(int level);  abstract Level create(int level); }
LevelFactory { public abstract Level create(int level);  abstract Level create(int level);  }