protected function findParentBlock($fullBlockName, $viewFileName)
    {
        $parentViewFile = $this->findParentViewFile($viewFileName);
        $viewFilesChain = $this->getViewFilesChain($parentViewFile);
        $savedContent = '';
        foreach ($viewFilesChain as $viewFile) {
            if ($this->viewBlocks($viewFile)->exists($fullBlockName)) {
                $savedContent = $this->viewBlocks($viewFile)->get($fullBlockName);
                break;
            }
        }
        return $savedContent;
    }