src/Helpers/FileHelperAsc.php
public static function chmod($path, $mode = 0755)
    {
        if ($path instanceof GenericOperationInterface) {
            return $path->chmod($mode);
        }
        return static::file($path)->chmod($mode);
    }
public static function chmod($path, $mode = 0755)
    {
        if ($path instanceof GenericOperationInterface) {
            return $path->chmod($mode);
        }
        return static::file($path)->chmod($mode);
    }
Perform 'chmod' operation
@param string|GenericOperationInterface $path File or Directory
@param int                              $mode
@return \React\Promise\PromiseInterface