title: I can't turn on fast renderers on Xamarin forms
body: <p>When I add <code>Forms.SetFlags("FastRenderers_Experimental");</code> as <a href="https://developer.xamarin.com/releases/xamarin-forms/xamarin-forms-2.4/2.4.0-pre1/" rel="nofollow noreferrer">https://developer.xamarin.com/releases/xamarin-forms/xamarin-forms-2.4/2.4.0-pre1/</a> states, I get the following error: <code>'Forms' does not contain a definition for 'SetFlags'</code>. Indeed, I can't find one. So how is this meant to work? Is there another step?</p>