Merge pull request #11378 from creative-commoners/pulls/6/add-import

FIX Import Deprecation class

src/View/ViewableData.php

@@ -20,6 +20,7 @@
 use SilverStripe\ORM\FieldType\DBHTMLText;
 use SilverStripe\View\SSViewer;
 use UnexpectedValueException;
+use SilverStripe\Dev\Deprecation;
 
 /**
  * A ViewableData object is any object that can be rendered into a template/view.