in src/core/distributor.js [42:62]
simple: function(nodes){
var numLayers = distributor.estimateRequiredLayers(nodes);
var layers = [];
for(var i=0;i<numLayers;i++){
layers.push([]);
}
nodes.forEach(function(node, i){
var mod = i%numLayers;
layers[mod].push(node);
var stub = node;
for(var j=mod-1;j>=0;j--){
stub = stub.createStub(options.stubWidth);
layers[j].push(stub);
}
});
return layers;
},