public function addSource(string $directive, string $path): self
    {
        switch ($directive) {
            case 'child':
            case 'frame':
            case 'frame-src':
                if ($this->supportOldBrowsers) {
                    $this->policies['child-src']['allow'][] = $path;
                    $this->policies['frame-src']['allow'][] = $path;
                    return $this;
                }
                $directive = 'child-src';
                break;
            case 'connect':
            case 'socket':
            case 'websocket':
                $directive = 'connect-src';
                break;
            case 'font':
            case 'fonts':
                $directive = 'font-src';
                break;
            case 'form':
            case 'forms':
                $directive = 'form-action';
                break;
            case 'ancestor':
            case 'parent':
                $directive = 'frame-ancestors';
                break;
            case 'img':
            case 'image':
            case 'image-src':
                $directive = 'img-src';
                break;
            case 'media':
                $directive = 'media-src';
                break;
            case 'object':
                $directive = 'object-src';
                break;
            case 'js':
            case 'javascript':
            case 'script':
            case 'scripts':
                $directive = 'script-src';
                break;
            case 'style':
            case 'css':
            case 'css-src':
                $directive = 'style-src';
                break;
            case 'worker':
                $directive = 'worker-src';
                break;
        }
        $this->policies[$directive]['allow'][] = $path;
        return $this;
    }