title: Graphviz ignores rank attribute if no edges between nodes
body: <p>I'musing Graphviz to render some hierarchical structure. So far the use of subgraphs has been sub-optimal for achieving what I'm looking for.</p>
  
  <p><strong>This</strong> is what I would like to get</p>
  
  <p><a href="https://i.stack.imgur.com/KtdgJ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KtdgJ.png" alt="enter image description here"></a></p>
  
  <p><em>(colors represent different tiers in the hierarchy so they need to follow this order)</em>. For making this image I used invisible links, but that's really not an option in a real world scenario.</p>
  
  <p>However, at the moment this is what I'm getting
  <a href="https://i.stack.imgur.com/j6tUY.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/j6tUY.png" alt="enter image description here"></a></p>
  
  <p>using this .dot file</p>
  
  <pre><code>graph {
      // Global config
      rankdir=BT
      node [style="filled" fontcolor="white" shape="box"]
      // Rank (hierarchies)
      { rank=same; 258 }
      { rank=same; 259 }
      { rank=same; 260 }
      { rank=same; 261 262 }
      // Nodes
      // Tasks
      258 [label="John Cleese" fillcolor="#E8B04D"]
      // Project Goals
      259 [label="Michael Palin" fillcolor="#C0C56B"]
      // Identities
      260 [label="Eric Idle" fillcolor="#FF8D61"]
      // Virtues
      261 [label="Graham Chapman" fillcolor="crimson"]
      262 [label="Terry Jones" fillcolor="crimson"]
      // Edges
      259 -- 260 [style="bold" color="#3790af"]
  }
  </code></pre>
  
  <p><strong>Is it posible for Graphviz to honor rank before edges? If so, how would I proceed?</strong></p>