<graph  file-name="graphs/nice_graph" rankdir="LR">

<node   id="a" label="node1" fontsize="9" fontname="Arial"/>
<node   id="b" label="node2" fontsize="9" fontname="Arial"/>
<node   id="c" label="node3" fontsize="9" fontname="Arial"/>
<node   id="d" label="node4" fontsize="9" fontname="Arial"/>
<edge   from="a" to="b" fontname="Arial" fontsize="9" label="edge1" weight="0.2"/>
<edge   from="b" to="c" fontname="Arial" fontsize="9" label="edge2" weight="0.6"/>
<edge   from="b" to="d" fontname="Arial" fontsize="9" label="edge3" weight="0.5"/>
</graph>