title: Graphviz: how to arrange nodes with circo layout
body: <p>I'm trying to draw a graph with circle topology.</p>
  
  <p>Here is what I'm expecting to see:
  <img src="https://i.stack.imgur.com/LBSco.png" alt="enter image description here"></p>
  
  <p>Here is my gv file:</p>
  
  <pre><code>digraph g1 {
      layout="circo";
      node [shape = doublecircle]; N4 N6;
      node [shape = circle];
      N0 -&gt; N1 [ label = "{1,0}"];
      N1 -&gt; N2 [ label = "{1,0}"];
      N2 -&gt; N3 [ label = "{1,0}"];
      N3 -&gt; N4 [ label = "{1,0}"];
      N4 -&gt; N5 [ label = "{1,0}"];
      N5 -&gt; N6 [ label = "{1,0}"];
      N6 -&gt; N0 [ label = "{1,0}"];
  
      N0 -&gt; N4 [ label = "{1,0}"];
      N1 -&gt; N5 [ label = "{1,0}"];
      N2 -&gt; N6 [ label = "{1,0}"];
      N3 -&gt; N0 [ label = "{1,0}"];
      N4 -&gt; N1 [ label = "{1,0}"];
      N5 -&gt; N2 [ label = "{1,0}"];
      N6 -&gt; N3 [ label = "{1,0}"];    
  }
  </code></pre>
  
  <p>And here is an output image for graph above:
  <img src="https://i.stack.imgur.com/F4z5f.png" alt="enter image description here"></p>
  
  <p>How can I arrange nodes in graphviz to make it look like <a href="https://i.stack.imgur.com/LBSco.png" rel="noreferrer">1</a>?</p>