NSMutableArray array = NSMutableArray.CLASS.arrayWithCapacity(3);
assertEquals(0, array.count());
array.addObject(NSString.stringWithString("Hello"));
array.addObject("Goodbye");
assertEquals(2, array.count());
assertEquals("(\n Hello,\n Goodbye\n)", array.description());
NSObject first = array.objectAtIndex(0);
assertEquals(NSString.stringWithString("Hello"), first);
NSString firstAsString = Rococoa.cast(first, NSString.class);