Implement Twig_ExtensionInterface::getName

Class CSSFromHTMLExtractor\Twig\Extension contains 1 abstract method and
must therefore be declared abstract or implement the remaining methods
(Twig_ExtensionInterface::getName)

Author: tvlooy

src/Twig/Extension.php

@@ -51,4 +51,9 @@ public function buildCriticalCssFromSnippets()
     {
         return $this->pageSpecificCssService->buildExtractedRuleSet();
     }
-}
+
+    public function getName()
+    {
+        return 'css-form-html-extractor';
+    }
+}