public Geometry ToThick()
{
var nodeLookup = Nodes.ToDictionary(n => n.Id, n => n.ToThick());
var wayLookup = Ways.ToDictionary(w => w.Id, w => w.ToThick(nodeLookup));
var relations = Relations.Select(r => r.ToThick(wayLookup));
return(new Geometry(nodeLookup.Values.ToArray(), wayLookup.Values.ToArray(), relations.ToArray()));
}