Merge pull request #10 from krzysztof-pyrzyk-ah/bugifx/fatal-error-wh…

…en-no-result-cache-provided

Fix fatal error when no cache provided in constructor

src/CssFromHTMLExtractor.php

@@ -56,7 +56,7 @@ public function __construct(Cache $resultCache = null)
         $this->cssConverter = new CssSelectorConverter();
 
         $this->resultCache = is_null($resultCache) ? new ArrayCache() : $resultCache;
-        $this->cachedRules = (array)$resultCache->fetch('cachedRules');
+        $this->cachedRules = (array)$this->resultCache->fetch('cachedRules');
     }
 
     public function getCssStore()