Computing the positions of a Layout without Viewer.display

[<schoellhorn AT ifm.uni-mannheim.de>]

Hi,

I am working at a graph visualization and I'd like to compute the
xyz-coordinates of the graph via the Layout mechanism and store the positions
in the graph (and finally export them to DGS). 

Currently I only was able to achive this via Graph.display like this: 

<code>
                Layout layout = Layouts.newLayoutAlgorithm();
                layout.setSendNodeInfos(true);          
                
                // Viewer
                Viewer v = graph.display(false);
                
                // Pipe 
                ViewerPipe pipe = v.newViewerPipe();
                pipe.addAttributeSink(graph);
                
                v.enableAutoLayout(layout);
                
                Thread.sleep(5000);
                
                
                pipe.pump();
</code>

On our server we only have a headless env - so this approach will not work. 
How
would I have to apply "Layout" on the Graph so the xyz-Attribut is updated? 

Thanks in advance!
Tino