How do you set the font size on a UIBarButtonItem?

Objective-C:

NSUInteger fontSize = 20;
UIFont *font = [UIFont boldSystemFontOfSize:fontSize];
NSDictionary *attributes = @{NSFontAttributeName: font};

UIBarButtonItem *item = [[UIBarButtonItem alloc] init];

[item setTitle:@"Some Text"];
[item setTitleTextAttributes:attributes forState:UIControlStateNormal];

self.navigationItem.rightBarButtonItem = item;

Swift:

let fontSize:CGFloat = 20;
let font:UIFont = UIFont.boldSystemFont(ofSize: fontSize);
let attributes:[String : Any] = [NSFontAttributeName: font];
    
let item = UIBarButtonItem.init();
    
item.title = "Some Text";
item.setTitleTextAttributes(attributes, for: UIControlState.normal);
    
self.navigationItem.rightBarButtonItem = item;