[graph-tool] Hierarchical Tree layout with transmission date

It is possible to draw networks in hierarchical tree layout positioned by transmission date? Something similar to this: <http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com/file/t496236/example.png> -- Sent from: http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com/