src/Control/Middleware/HTTPCacheControlMiddleware.php
public function generateHeadersFor(HTTPResponse $response)
    {
        return array_filter([
            'Last-Modified' => $this->generateLastModifiedHeader(),
            'Vary' => $this->generateVaryHeader($response),
            'Cache-Control' => $this->generateCacheHeader(),
            'Expires' => $this->generateExpiresHeader(),
        ]);
    }
public function generateHeadersFor(HTTPResponse $response)
    {
        return array_filter([
            'Last-Modified' => $this->generateLastModifiedHeader(),
            'Vary' => $this->generateVaryHeader($response),
            'Cache-Control' => $this->generateCacheHeader(),
            'Expires' => $this->generateExpiresHeader(),
        ]);
    }
public function generateHeadersFor ( HTTPResponse $ response ) { return array_filter ( [ 'Last-Modified' => $ this -> generateLastModifiedHeader ( ) , 'Vary' => $ this -> generateVaryHeader ( $ response ) , 'Cache-Control' => $ this -> generateCacheHeader ( ) , 'Expires' => $ this -> generateExpiresHeader ( ) , ] ) ; }
Generate all headers to output

@param HTTPResponse $response
@return array
Generate all headers to output