title: Can I simultaneously apply styles to many DOT nodes taken from multiple subgraphs?
body: <p>Consider this DOT sample:</p>
  
  <pre><code>digraph Foo
  {
      subgraph clusterA
      {
          A -&gt; B;
      }
  
      subgraph clusterB
      {
          X -&gt; Y;
      }
  
      subgraph connection_type_1
      {
          edge [color=red];
          A -&gt; Y;
      }
  
      subgraph connection_type_1
      {
          edge [color=green];
          B -&gt; X;
      }
  
      subgraph node_type_1
      {
          node [style=filled, color=".5,.5,.5"]; // THIS LINE DOESN'T WORK
          X [label="foo"];
          A;
      }
  }
  </code></pre>
  
  <p>The structure is set out in the two clusters and the edges are added later in semantically/cosmetically equivalent groups. The edges are coloured as expected.</p>
  
  <p>But this doesn't work with styling nodes. The marked line has no effect unless I move it into one of the <code>cluster*</code> subgraphs, but then it applies to all nodes within that subgraph.</p>
  
  <p>What's odd is that <code>label=foo</code> works in the final subgraph, whereas <code>style</code> doesn't.</p>
  
  <p>I have a feeling that the answer is going to be "you can only set node attributes the first time you mention them", but is there a way to say "the following nodes, wherever they are, should all have the following attributes"?</p>