src/Control/Middleware/HTTPCacheControlMiddleware.php
protected function generateCacheHeader()
    {
        $cacheControl = [];
        foreach ($this->getDirectives() as $directive => $value) {
            if ($value === true) {
                $cacheControl[] = $directive;
            } else {
                $cacheControl[] = $directive . '=' . $value;
            }
        }
        return implode(', ', $cacheControl);
    }
protected function generateCacheHeader()
    {
        $cacheControl = [];
        foreach ($this->getDirectives() as $directive => $value) {
            if ($value === true) {
                $cacheControl[] = $directive;
            } else {
                $cacheControl[] = $directive . '=' . $value;
            }
        }
        return implode(', ', $cacheControl);
    }
protected function generateCacheHeader ( ) { $ cacheControl = [ ] ; foreach ( $ this -> getDirectives ( ) as $ directive => $ value ) { if ( $ value === true ) { $ cacheControl [ ] = $ directive ; } else { $ cacheControl [ ] = $ directive . '=' . $ value ; } } return implode ( ', ' , $ cacheControl ) ; }
Generate the cache header

@return string
Generate the cache header