/** * {@inheritdoc} */ public function process(\Magento\Framework\View\Asset\PreProcessor\Chain $chain) { $chain->setContentType('less'); $tmpFile = $this->fileGenerator->generateFileTree($chain); $cssContent = $this->adapter->process($tmpFile); $cssTrimmedContent = trim($cssContent); if (!empty($cssTrimmedContent)) { $chain->setContent($cssContent); } $chain->setContentType('css'); }