replace deprecated sizeWithFont with sizeWithAttributes

How can I produce following code using sizeWithAttributes method:

CGFloat labelWidth = [label.text sizeWithFont:label.font].width;

I need to have label width!

Use like this

CGSize size = [string sizeWithAttributes:
                       @{NSFontAttributeName:
                         [UIFont systemFontOfSize:17.0f]}];