title: Finding all cycles in a directed graph
body: <p>How can I find (iterate over) ALL the cycles in a directed graph from/to a given node?</p>
  
  <p>For example, I want something like this:</p>
  
  <pre><code>A-&gt;B-&gt;A
  A-&gt;B-&gt;C-&gt;A
  </code></pre>
  
  <p>but not:
      B->C->B</p>