title: I am getting a "duplicate association path" error in the NHibernate Criteria when accessing the same table twice
body: <p>I have  a CreateCriteria that adds a join to the same table twice with different aliases:</p>
  
  <pre><code>aCriteria.CreateCriteria("Color", "co").Add(Expression.In("co.ColorId", bikush.Color.Select(x =&gt; x.ColorId).ToList()));
  
  aCriteria.CreateCriteria("Color","fco").Add(Expression.In("fco.ColorId",bikush.FCColor.Select(x =&gt; x.ColorId).ToList()));
  </code></pre>
  
  <p>I'm getting the error "duplicate association path" </p>
  
  <p>Here is the SQL I want to generate:</p>
  
  <p><code>SELECT b.BikushId, c.[Name] AS PlainColor, fc.[Name] AS FancyColor FROM Bikush b INNER JOIN BikushInColor clt ON clt.BikushId = b.BikushId INNER JOIN Color c ON clt.ColorId = c.ColorId INNER JOIN BikushInFCColor bifc ON b.BikushId = bifc.BikushId INNER JOIN Color fc ON bifc.ColorId =fc.ColorId</code></p>
  
  <p>Is there anyway around this using the CriteriaApi of Nhibernate?</p>
  
  <p>Thanks</p>