title: How to add an annotation outside of a node in Graphviz' dot?
body: <p>I am very new to Dot and trying to visualize a callgraph with Dot and Zest in Eclipse. And I would like to annotate nodes with kind of annotation (OK and Failed on the pic.).</p>
  
  <p><img src="https://i.stack.imgur.com/NlAi9.png" alt="Annotated graph I want to get"></p>
  
  <p>Is there any common way to do this for Dot or Zest?</p>