private function cacheDirectory(): string
    {
        $cacheDirectory = (string) $this->cacheDirectory;

        if ('' === $cacheDirectory && false === \is_writable($cacheDirectory))
        {
            $cacheDirectory = \sys_get_temp_dir();
        }

        return \rtrim($cacheDirectory, '/');
    }
private function cacheDirectory(): string
    {
        $cacheDirectory = (string) $this->cacheDirectory;

        if ('' === $cacheDirectory && false === \is_writable($cacheDirectory))
        {
            $cacheDirectory = \sys_get_temp_dir();
        }

        return \rtrim($cacheDirectory, '/');
    }
private function cacheDirectory ( ) : string { $ cacheDirectory = ( string ) $ this -> cacheDirectory ; if ( '' === $ cacheDirectory && false === \ is_writable ( $ cacheDirectory ) ) { $ cacheDirectory = \ sys_get_temp_dir ( ) ; } return \ rtrim ( $ cacheDirectory , '/' ) ; }
Receive cache directory path.

@return string
Receive cache directory path .