src/Control/Middleware/HTTPCacheControlMiddleware.php
protected function generateVaryHeader(HTTPResponse $response)
    {
        // split the current vary header into it's parts and merge it with the config settings
        // to create a list of unique vary values
        $vary = $this->getVary();
        if ($response->getHeader('Vary')) {
            $vary = $this->combineVary($vary, $response->getHeader('Vary'));
        }
        if ($vary) {
            return implode(', ', $vary);
        }
        return null;
    }
protected function generateVaryHeader(HTTPResponse $response)
    {
        // split the current vary header into it's parts and merge it with the config settings
        // to create a list of unique vary values
        $vary = $this->getVary();
        if ($response->getHeader('Vary')) {
            $vary = $this->combineVary($vary, $response->getHeader('Vary'));
        }
        if ($vary) {
            return implode(', ', $vary);
        }
        return null;
    }
protected function generateVaryHeader ( HTTPResponse $ response ) { // split the current vary header into it's parts and merge it with the config settings // to create a list of unique vary values $ vary = $ this -> getVary ( ) ; if ( $ response -> getHeader ( 'Vary' ) ) { $ vary = $ this -> combineVary ( $ vary , $ response -> getHeader ( 'Vary' ) ) ; } if ( $ vary ) { return implode ( ', ' , $ vary ) ; } return null ; }
Generate vary http header

@param HTTPResponse $response
@return string|null
Generate vary http header