title: Increasing distance between subgraphs
body: <p>I have the following code:</p>
  
  <pre><code>digraph g {
  graph [rankdir="LR" ,compound="true" ];
      subgraph cluster0 {
          graph [label="Ready\n\nAllowed Purchaser Operations:\noperation1,operation2\n\nAllowed Supplier Operations:\noperation1,operation3"  ];
          1 [ shape="none" ,fontcolor="white"  ];
      };
      subgraph cluster2 {
          graph [label="Paused\n\nAllowed Purchaser Operations:\noperation1,operation3\n\nAllowed Supplier Operations:\noperation2,operation3" ];
          3 [ shape="none" ,fontcolor="white"  ];
      };
      subgraph cluster4 {
          graph [label="Completed\n\nAllowed Purchaser Operations:\noperation4\n\nAllowed Supplier Operations:\noperation4" ];
          5 [ shape="none" ,fontcolor="white"  ];
      };
      1 -&gt; 3 [ ltail="cluster0" ,lhead="cluster2" ,comment="6"  ];
      1 -&gt; 5 [ ltail="cluster0" ,lhead="cluster4" ,comment="7"  ];
      3 -&gt; 1 [ ltail="cluster2" ,lhead="cluster0" ,comment="8"  ];
      3 -&gt; 5 [ ltail="cluster2" ,lhead="cluster4" ,comment="9"  ];
  }
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/Y9SeH.jpg" alt="enter image description here"></p>
  
  <p>I want to increase the distance between the subgraphs. I've tried using <code>len</code>, <code>margin</code>, <code>pad</code>, but the syntax I've tried doesn't work. Can somebody help me? </p>