public function getEtags()
    {
        $etag = '';

        if ($this->data instanceof ArrayableInterface) {
            $this->data = $this->data->toArray();
        }

        foreach ( $this->data as $item ) {
            $item = new Resource($item);
            $etag .= $item->getEtag();
            unset($item);
        }

        return md5( $etag );
    }
public function getEtags()
    {
        $etag = '';

        if ($this->data instanceof ArrayableInterface) {
            $this->data = $this->data->toArray();
        }

        foreach ( $this->data as $item ) {
            $item = new Resource($item);
            $etag .= $item->getEtag();
            unset($item);
        }

        return md5( $etag );
    }
public function getEtags ( ) { $ etag = '' ; if ( $ this -> data instanceof ArrayableInterface ) { $ this -> data = $ this -> data -> toArray ( ) ; } foreach ( $ this -> data as $ item ) { $ item = new Resource ( $ item ) ; $ etag .= $ item -> getEtag ( ) ; unset ( $ item ) ; } return md5 ( $ etag ) ; }
Return ETag based on collection of items

@return string    md5 of all ETags
Return ETag based on collection of items