title: graphviz: record node with a bold title
body: <p>I'm trying to use graphviz to do something similar to UML class diagrams.</p>
  
  <p>I wonder whether there is a way to make a node of style 'register' have its first field in a bold font, to make it different from the other fields.</p>
  
  <p>My node looks like this:</p>
  
  <pre><code>digraph i { 
    "node" [
      label = "&lt;f0&gt; title | &lt;f1&gt; index | ... | &lt;f2&gt; field1 | &lt;f3&gt; field2"
      shape = "record"
    ];  
  }
  </code></pre>
  
  <p>I tried this but it doesn't work: (embedding html)</p>
  
  <pre><code>digraph i { 
    "node" [
      label = "&lt;f0&gt; &lt;B&gt;title&lt;/B&gt; | &lt;f1&gt; index | ... | &lt;f2&gt; field1 | &lt;f3&gt; field2"
      shape = "record"
    ];  
  }
  </code></pre>