<?xml version="1.0" encoding="utf-8"?>
<graph>
  <name>Test Graph</name>
  <vertex name="v1" />
  <vertex name="v2" />
  <vertex name="v3" />
  <vertex name="v4" />
  <edge name="e1" from="v1" to="v2" />
  <edge name="e3" from="v1" to="v4" />
  <edge name="e4" from="v4" to="v2" />
  <edge name="e5" from="v4" to="v3" />
  <edge name="e6" from="v4" to="v1" />
</graph>