src/CachePlugin.php
protected function getETag(CacheItemInterface $cacheItem)
    {
        $data = $cacheItem->get();

        foreach ($data['etag'] as $etag) {
            if (!empty($etag)) {
                return $etag;
            }
        }
    }
protected function getETag(CacheItemInterface $cacheItem)
    {
        $data = $cacheItem->get();

        foreach ($data['etag'] as $etag) {
            if (!empty($etag)) {
                return $etag;
            }
        }
    }
protected function getETag ( CacheItemInterface $ cacheItem ) { $ data = $ cacheItem -> get ( ) ; foreach ( $ data [ 'etag' ] as $ etag ) { if ( ! empty ( $ etag ) ) { return $ etag ; } } }
Get the ETag from the cached response.

@param \Psr\Cache\CacheItemInterface $cacheItem

@return string|null
Get the ETag from the cached response .