assertEquals("Should get elements in correct order",
"A", bag.toArray()[0]);
assertEquals("Should get elements in correct order",
"B", bag.toArray()[1]);
assertEquals("Should get elements in correct order",
"C", bag.toArray()[2]);
assertEquals("Should get first key",
"A", ((SortedBag)bag).first());
assertEquals("Should get last key",
"D", ((SortedBag)bag).last());
}