Formatted Label with Xamarin.Forms

Can someone please show me how to use Xamarin.Forms.Label.FormattedText correctly?

I'm using Xamarin.Forms to write a Carousel based app, when I try

Label IntroductionTextLabel = new Label();
IntroductionTextLabel.FormattedText = "Test";

I get this error:

"'Xamarin.Forms.Label' does not contain a definition for 'FormattedText' and no extension method 'FormattedText' accepting a first argument of type 'Xamarin.Forms.Label' could be found (are you missing a using directive or an assembly reference?)"

Perhaps it's the version of Xamarin I'm currently using...

The next step would be using this to display some HTML.

Thanks for any help.