<?xml version="1.0" encoding="UTF-8"?>
<graph>
  <node key="Alpha" color="lightblue" />
  <node key="Beta" color="orange" />
  <node key="Gamma" color="lightgreen" />
  <node key="Delta" color="pink" />
  <link from="Alpha" to="Beta" />
  <link from="Alpha" to="Gamma" />
  <link from="Beta" to="Beta" />
  <link from="Gamma" to="Delta" />
  <link from="Delta" to="Alpha" />
</graph>
