Uncaught Error: Class 'Nmap' not found

[Gifford47]

Hey! Hey! Hey!
i just wanted to try nmap, but php doesn't find the class "Nmap".
i installed nmap via "composer require willdurand/nmap" successfully.
I created the following script:
test.php:
`<?php

require DIR . '/vendor/autoload.php';

$nmap = new Nmap();
//$nmap->scan([ 'williamdurand.fr' ], [ 21, 22, 80 ]);
//$hosts = Nmap::create()->scan([ 'williamdurand.fr' ]);
//$ports = $hosts->getOpenPorts();
//echo $ports;

?>
`

and my error output:
PHP Fatal error: Uncaught Error: Class 'Nmap' not found in /var/www/start/nmap/test.php

Where's my mistake?

[mr2017x]

Got the same error, actually i thought i would stuck with compose but it seems as the build is error?