doLayout method
Implementation
@override
void doLayout(Context context, Graph graph, num width, num height) {
num w = center[0].convert(width);
num h = center[1].convert(height);
Random random = Random();
double scaleFactor = 0.9;
for (var node in graph.nodes) {
node.x = (random.nextDouble() - 0.5) * scaleFactor * width + w;
node.y = (random.nextDouble() - 0.5) * scaleFactor * height + h;
}
}